Abstract: <p>Clavicles and interclavicles are plesiomorphically present in Reptilia. However, several groups show reduction or even loss of these elements. Crocodylimorpha, e.g., lost the clavicles, whereas dinosaurs are generally interpreted to only preserve the clavicles, the theropod furcula representing an unique case of fused clavicles. In sauropods, reports of clavicles are relatively frequent in non-titanosauriforms. These elements are elongated, curved, and rather stout bones with a spatulate and a bifurcate end. However, they were always found as single bones, and differ from the relatively short and unbifurcated clavicles found articulated with the scapulae of basal sauropodomorphs.<br /> Elements from the Howe Quarry (Late Jurassic; Wyoming, USA) shed new light on these interpretations. Besides the elongated, curved bones (herein named morphotype A), also pairs of symmetric, L-shaped bones were recovered (morphotype B), associated with diplodocid dorsal and cervical vertebrae. Elements resembling morphotype B - articulated between the scapulae - have recently been reported from a diplodocid found near Tensleep, Wyoming. Taphonomic evidence, as well as the fact that they were preserved in symmetrical pairs, therefore implies that morphotype B represents the true sauropod clavicles.<br /> Contrary to earlier reports, morphotype A elements from the Howe Quarry, as well as of previously reported specimens show a symmetry plane following the long axis of the elements. It is thus possible that the morphotype A elements were single bones from the body midline. The only such element present in the pectoral girdle of tetrapods are the interclavicle and the furcula. Comparison with crocodilian and lacertiform interclavicles indicates that the bifurcate end of the sauropod elements might represent the reduced transverse processes of the anterior end, and the spatulate end would have covered the coracoids or sternal plates ventrally.<br /> The presence of both clavicles and interclavicles in the pectoral girdle stiffens the anterior trunk, and enhances considerably its stability. Such an enforcement might have been needed in diplodocids due to the strong lateral forces induced to the fore-limbs by the posteriorly placed center of mass (due to shorter fore- than hind-limbs), as well as lateral movements of the enormously elongated necks and tails. The absence of clavicles and interclavicles in titanosauriforms coincides with the development of wide-gauge locomotion style.<br /> The presence of interclavicles in sauropods supports the recently proposed homology of the furcula with the interclavicle, instead of representing fused clavicles. Interclavicles were thus not lost, but may have remained cartilaginous or have yet to be found in basal dinosauriforms.</p>
Abstract: <p>Ossified gastralia, clavicles and sternal ribs are known in a variety of reptilians, including dinosaurs. In sauropods, however, the identity of these bones is controversial. The peculiar shapes of these bones complicate their identification, which led to various differing interpretations in the past. Here we describe different elements from the chest region of diplodocids, found near Shell, Wyoming, USA. Five morphotypes are easily distinguishable: (A) elongated, relatively stout, curved elements with a spatulate and a bifurcate end resemble much the previously reported sauropod clavicles, but might actually represent interclavicles; (B) short, L-shaped elements, mostly preserved as a symmetrical pair, probably are the real clavicles, as indicated by new findings in diplodocids; (C) slender, rod-like bones with rugose ends are highly similar to elements identified as sauropod sternal ribs; (D) curved bones with wide, probably medial ends constitute the fourth morphotype, herein interpreted as gastralia; and (E) irregularly shaped elements, often with extended rugosities, are included into the fifth morphotype, tentatively identified as sternal ribs and/or intercostal elements. To our knowledge, the bones previously interpreted as sauropod clavicles were always found as single bones, which sheds doubt on the validity of their identification. Various lines of evidence presented herein suggest they might actually be interclavicles \textendash which are single elements. This would be the first definitive evidence of interclavicles in dinosauromorphs. Previously supposed interclavicles in the early sauropodomorph Massospondylus or the theropods Oviraptor and Velociraptor were later reinterpreted as clavicles or furculae. Independent from their identification, the existence of the reported bones has both phylogenetic and functional significance. Their presence in non-neosauropod Eusauropoda and Flagellicaudata and probable absence in rebbachisaurs and Titanosauriformes shows a clear character polarity. This implicates that the ossification of these bones can be considered plesiomorphic for Sauropoda. The proposed presence of interclavicles in sauropods may give further support to a recent study, which finds a homology of the avian furcula with the interclavicle to be equally parsimonious to the traditional theory that furcula were formed by the fusion of the clavicles. Functional implications are the stabilizing of the chest region, which coincides with the development of elongated cervical and caudal vertebral columns or the use of the tail as defensive weapon. The loss of ossified chest bones coincides with more widely spaced limbs, and the evolution of a wide-gauge locomotor style.</p>
Abstract: <p>A partial plesiosauroid skull from the São Gião Formation (Toarcian, Lower Jurassic) of Alhadas, Portugal is re-evaluated and described as a new taxon, Lusonectes sauvagei gen. et sp. nov. It has a single autapomorphy, a broad triangular parasphenoid cultriform process that is as long as the posterior interpterygoid vacuities, and also a unique character combination, including a jugal that contacts the orbital margin, a distinct parasphenoid\textendashbasisphenoid suture exposed between the posterior interpterygoid vacuities, lack of an anterior interpterygoid vacuity, and striations on the ventral surface of<br /> the pterygoids. Phylogenetic analysis of Jurassic plesiosauroids places Lusonectes as outgroup to \textquotedblleftmicrocleidid elasmosaurs\textquotedblright, equivalent to the clade Plesiosauridae. Lusonectes sauvagei is the only diagnostic plesiosaur from Portugal, and the westernmost occurrence of any plesiosaurian in Europe.</p>
Notes: <p>In press but proofs already available online (24June2011)</p>
Abstract: <p>The basal part of the Triassic-Jurassic (Rhaetian-Sinemurian) Kap Stewart Formation, exposed at Jameson Land, East Greenland, yields an extensive coprolite collection from black, parallel-laminated mudstone (\textquotedblleftpaper shale\textquotedblright), representing an open lacustrine system. Preliminary investigations show three different types of coprolites: elongated cylindrical masses, composed of irregularly wrapped layers; elongated cylindrical masses with constriction marks; and spirally-coiled specimens.</p>
Abstract: A forelimb of a new sauropod dinosaur (Angolatitan adamastor n. gen. et sp.) from the Late Turonian of Iembe (Bengo Province) represents the first dinosaur discovery in Angola, and is one of the few occurrences of sauropod dinosaurs in sub-Saharan Africa collected with good chronological controls. The marginal marine sediments yielding the specimen are reported to be late Turonian in age and, thus it represents a non-titanosaurian sauropod in sub-Saharan
Africa at a time taken to be dominated by titanosaurian forms. Moreover, Angolatitan adamastor is the only basal
Somphospondyli known in the Late Cretaceous which implies in the existence of relict forms in Africa.
Abstract: Although the Late Jurassic of Portugal has provided abundant dinosaur fossils, material from the Early Cretaceous is scarce. This paper reports new cranial and postcranial material of the theropod dinosaur Baryonyx walkeri found in the Barremian (Papo Seco Formation) of Portugal. This specimen, found at Praia das Aguncheiras, Cabo Espichel, consists of a partial dentary, isolated teeth, pedal ungual, two calcanea, presacral and caudal vertebrae, fragmentary pubis, scapula, and rib fragments. It represents the most complete spinosaurid yet discovered in the Iberian Peninsula and the most complete dinosaur from the Early Cretaceous of Portugal. This specimen is confidently identified as a member of Baryonychinae due to the presence of conical teeth with flutes and denticles in a dentary rosette. The specimen ML1190 shares the following characteristics with Baryonyx walkeri: enamel surface with small (nearly vertical) wrinkles, variable denticle size along the carinae, 6â7 denticles per mm, wrinkles forming a 45 degree angle near the carinae, and tooth root longer than crown. In addition, dubious taxa based on teeth morphology such as Suchosaurus cultridens (Owen, 1840â1845), and Suchosaurus girardi (Sauvage 1897â98; Antunes & Mateus 2003) are discussed, based on comparisons with well-known material such as Baryonyx walkeri Charig & Milner, 1986. Suchosaurus cultridens and S. girardi are considered as nomina dubia due to the lack of diagnostic apomorphies, but both specimens are referred to Baryonychinae incertae sedis.
Abstract: <p>Eleven new tracks from the Upper Jurassic of Portugal are described and attributed to the stegosaurian ichnogenus Deltapodus. One track exhibits exceptionally well-preserved<br /> impressions of skin on the plantar surface, showing the stegosaur foot to be covered by closely spaced skin tubercles of ca. 6 mm in size. The Deltapodus specimens from the<br /> Aalenian of England represent the oldest occurrence of stegosaurs and imply an earlier cladogenesis than is recognized in the body fossil record.</p>
Abstract: <p>Although diplodocoid sauropods from Africa and the Americas are well known, their European record remains largely neglected. Here we redescribe Dinheirosaurus lourinhanensis from the Late Jurassic of Portugal. The holotype comprises two posterior cervical vertebrae, the dorsal series and a caudal centrum. Redescription demonstrates its validity on the basis of three autapomorphies: (1) posteriorly restricted ventral keel on posterior cervical vertebrae; (2) three small subcircular fossae posterior to the lateral coel on posterior cervical neural spines; (3) accessory lamina linking the hyposphene with base of the posterior centrodiapophyseal lamina in middle-posterior dorsal vertebrae. Phylogenetic analysis places Dinheirosaurus as the sister taxon to Supersaurus, and this clade forms the sister taxon to other diplodocines. However, this position should be treated with caution as Dinheirosaurus displays several plesiomorphic features absent in other diplodocids (including unbifurcated presacral neural spines, and dorsolaterally projecting diapophyses on dorsal vertebrae) and only four additional steps are required to place Dinheirosaurus outside of Flagellicaudata. We identify Amazonsaurus as the basal-most rebbachisaurid and recover Zapalasaurus outside of the South American Limaysaurinae, suggesting the biogeographic history of rebbachisaurids is more complex than previously proposed. Review of the European diplodocoid record reveals evidence for the earliest known diplodocid, as well as additional diplodocid remains from the Late Jurassic of Spain. A Portuguese specimen, previously referred to Dinheirosaurus, displays strong similarities to Apatosaurus from the contemporaneous Morrison Formation of North America, indicating the presence of a second Late Jurassic Portuguese diplodocid taxon. Along with Dinheirosaurus, these Portuguese remains provide further evidence for a Late Jurassic palaeobiogeographic connection between Europe and North America. No dicraeosaurids are currently known from Europe, but rebbachisaurids are present in the Early Cretaceous, with weak evidence for the earliest known representative from the Late Jurassic of Spain; however, more complete material is required to recognize early members of this clade.</p>
Abstract: The Upper Jurassic of Portugal has a rich vertebrate fauna well documented from both body and trace
fossils. Although the occurrence of crocodyles and pterosaurs is well documented from body fossils, trace fossils
from both groups were unknown until now. Here we describe an isolated crocodyle-like track from Praia da Peralta
and pterosaur tracks from the Kimmeridgian of Pedreira do Avelino, Sesimbra (Azóia Fm.) and Porto das Barcas,
Lourinhã (Lourinhã Fm.). An enigmatic track suggests the possible presence of a small, tail-dragging tetrapod.
Possible track-makers are suggested based on the known Late Jurassic vertebrate fauna of Portugal.
Abstract: <p>A portion of a left humerus from the Upper Maastrichtian of Vratsa district (NW Bulgaria)<br /> is shown to be from a non-avian theropod dinosaur: this is the first record of a<br /> dinosaur from Bulgaria. We describe this bone, suggest that it most likely pertains to an<br /> ornithomimosaur, and discuss the fossil record of other similar taxa of Late Cretaceous<br /> age that have been reported from Europe. To investigate the taphonomy of this fossil,<br /> rare earth element (REE) analysis is combined with strontium (Sr) isotope data to confirm<br /> that this Bulgarian dinosaur bone was initially fossilized in a terrestrial environment,<br /> then later re-worked into late Maastrichtian marine sediments.</p>
Abstract: New mosasaur fossils from Maastrichtian beds at Bentiaba, Angola, representing elements of the skull and postcranial axial skeleton from two individuals of the durophagous genus Globidens, are reported. Based on dental morphology, speciï¬cally the inï¬ated posterior surface and vertical sulci, the Bentiaba specimens are identiï¬ed as Globidens phosphaticus, a species deï¬ned by characters of a composite dentition from the Maastrichtian of Morocco. Comparisons indicate that G. phosphaticus is most closely related to G. schurmanni, from the late Campanian of South Dakota, the youngest north American Globidens species at about 72.5 Ma. The morphology of the premaxilla and its relationship with the maxillae is unique among mosasaurs,
and supports the taxonomic validity of G. phosphaticus. In contrast with earlier species of the genus, G. phosphaticus is currently known from north and west Africa, the Middle East and the central eastern margin of South America, suggesting it may have been restricted to the Maastrichtian tropical zone as previously hypothesised.
Abstract: <p>A newly discovered dinosaur track-assemblage from the Upper Jurassic Lourinha~ Formation<br /> (Lusitanian Basin, central-west Portugal), comprises medium- to large-sized sauropod<br /> tracks with well-preserved impressions of soft tissue anatomy, stegosaur tracks and<br /> tracks from medium- to large-sized theropods. The 400-m-thick Lourinha~ Formation<br /> consists of mostly aluvial sediments, deposited during the early rifting of the Atlantic<br /> Ocean in the Kimmeridgian and Tithonian. The stratigraphic succession shows several<br /> shifts between flood-plain mud and fluvial sands that favour preservation and fossilization<br /> of tracks. The studied track-assemblage is found preserved as natural casts on the<br /> underside of a thin bivalve-rich carbonate bed near the Tithonian\textendashKimmeridgian<br /> boundary. The diversity of the tracks from the new track assemblage is compared with<br /> similar faunas from the Upper Jurassic of Asturias, Spain and the Middle Jurassic Yorkshire<br /> Coast of England. The Portuguese record of Upper Jurassic dinosaur body fossils<br /> show close similarity to the track fauna from the Lourinha~ Formation. h Dinosaur<br /> tracks, Lusitanian Basin, Portugal, skin impressions, Upper Jurassic</p>
Abstract: <p>The Upper Jurassic of Portugal has a rich vertebrate fauna well documented from both body and trace fossils. Although the occurrence of crocodyles and pterosaurs is well documented from body fossils, trace fossils from both groups were unknown until now. Here we describe an isolated crocodyle-like track from Praia da Peralta and pterosaur tracks from the Kimmeridgian of Pedreira do Avelino, Sesimbra (Azóia Fm.) and Porto das Barcas, Lourinhã (Lourinhã Fm.). An enigmatic track suggests the possible presence of a small, tail-dragging tetrapod.<br /> Possible track-makers are suggested based on the known Late Jurassic vertebrate fauna of Portugal.</p>
Abstract: DINOSAUR EGGSHELL AND EMBRYO LOCALITIES IN LOURINHA
FORMATION, LATE JURASSIC, PORTUGAL
CASTANHINHA, Rui, Museu da Lourinhã, Lourinhã, Portugal; ARAÃJO, Ricardo, Museu
da Lourinhã, Lourinhã, Portugal; MATEUS, Octávio, Museu da Lourinhã & Universidade
Nova Lisboa (CICEGe/FCT), Lourinhã, Portugal
Four different localities from the Late Jurassic of Lourinhã formation with eggshells and
embryos were studied: Paimogo (lower Amoreira-Porto Novo member), Peralta (Praia
Azul member), Porto das barcas (Bombarral member) and Casal da Rôla (Amoreira-Porto
Novo member). All but Casal da Rôla have embryonic material. Preliminary results show
that eggshells from Paimogo correspond to obliquiprismatic morphotype (0.92mm thick),
similar to those from Morrison Formation. Within Paimogo site a different type of eggshell
was discovered, having a radial section of 153 μm with a mammilary layer measuring 65
μm. Porto das Barcas eggshells represent a discretispherulitic morphotype (1,23 mm thick).
This locality presents a nest 60-cm diameter containing many eggshells but an indeterminate
number of eggs. Some embryonic bones were discovered between the eggshells including
teeth and skull bones showing that the eggs belong to a saurischian, tentatively a sauropod
dinosaur. Peralta nest eggshells are preliminary ascribed to obliquiprismatic morphotype
(column: 0,56mm and mammilla: 0,21mm) probably related to Paimogoâs nest taxon
(Lourinhanosaurus). Peralta site bears embryonic bones namely small theropod teeth
associated with bone fragments, and unidentifiable dinosaur vertebra. Only eggshells have
been collected at Casal da Rôla (ML1194). The eggshells (0,78mm thick) are prismatic
morphotype and it was impossible to determine the pore system, the outer surface is smooth
with no ornamentation.
Lourinhã formation has the oldest sauropod and theropod nest with embryos known so far.
Abstract: NEW SPECIMENS OF ANGOLASAURUS BOCAGEI AND COMMENTS ON THE
EARLY RADIATIONS OF PLIOPLATECARPINE MOSASAURS
POLCYN, Michael, SMU, Dallas, TX, USA; JACOBS, Louis, SMU, Dallas, TX,
USA; MATEUS, Octávio, Museu da Lourinhã, Lourinhã, Portugal; SCHULP, Anne,
Natuurhistorisch Museum Maastricht, Maastricht, Netherlands
New, well preserved material of the Turonian mosasaur Angolasaurus bocagei from the
Tadi Beds of the Itombe Formation in northern Angola, allows detailed redescription of its
morphology and reassessment of its phylogenetic relationships. Angolasaurus had been
previously referred to the genus Platecarpus; however, phylogenetic analysis confirms the
valid taxonomic status of A. bocagei, and reconstructs that taxon within a clade that also
includes the genera Selmasaurus and Ectenosaurus. These forms are united by an elaborated
infrastapedial process of the quadrate and a unique ridge-like descending process of the
parietal forming the supraoccipital articulation, but also retain a relatively plesiomorphic
configuration of the braincase. That clade is united with all other plioplatecarpines by a
number of derived characters including the presence of a novel basicranial circulation
pattern. In Africa, North and South America, early plioplatecarpines are known by the
Middle Turonian and Angolasaurus and closely related forms appear by the Upper Turonian.
Selmasaurus and Ectenosaurus are a rare faunal component of the Santonian and Campanian
of North America. Platecarpus planifrons appears in the Coniacian of North America and
represents the plesiomorphic condition of the clade containing the remaining species of
Platecarpus and Plioplatecarpus, that appears in the Santonian and persist until the end of
the Cretaceous, reaching global distribution. The temporal and geographic distribution of
these radiations suggest influence of paleogeography and eustatic sea levels.
Abstract: The Cretaceous tropical Atlantic Ocean was the setting for an initial tectonically controlled late Aptian shallow water ( 300 m) connection between the northern and southern portions of the Atlantic, followed by a deep-water connection by the Turonian. Ocean currents changed with deepening of the South Atlantic and progressive widening of the Equatorial Atlantic Gateway. Aptian evaporite deposition came to a halt. The Albian-Turonian interval includes a trend toward increasing sea level and was characterized by globally warm sea surface temperatures. Productive areas of coastal upwelling led to the deposition of organic-rich sediments varying in position along the African coast with time, culminating in the Benguela Upwelling that commenced in the Miocene. The drift of Africa in the Late Cretaceous indicates that throughout most of this period, the coastal area around the fossil locality of Iembe, north of Luanda, Angola, lay in arid latitudes (15o S to 30o S), which are generally characterized by sparse vegetation. This presumption is consistent with the utter lack of macroscopic terrestrial plant debris washed into near shore sedimentary environments and indicates that organic rich marine shales have a minimal terrestrial carbon component. The connection of the North and South Atlantic oceans severed a direct terrestrial dispersal route between South America and Africa, but opened a north-south dispersal route for marine amniotes. This seaway was used by late Turonian mosasaurs and sea turtles as evidenced by Angolasaurus and a new turtle taxon close to Sandownia, both found at Iembe and derived from northern clades. The presence of a sauropod in late Turonian sediments, also from Iembe, suggests that this animal was tolerant of warm, arid conditions as the desert elephants of Namibia are today. Further, it suggests that the waning terrestrial dispersal route between South America and Africa was situated in a region where high temperature, low rainfall, and sparse vegetation would be expected to restrict the movement of more mesic and ecologically sensitive species.
Abstract: A newly discovered dinosaur track-assemblage from the Upper Jurassic LourinhaË Formation (Lusitanian Basin, central-west Portugal), comprises medium- to large-sized sauropod tracks with well-preserved impressions of soft tissue anatomy, stegosaur tracks and tracks from medium- to large-sized theropods. The 400-m-thick LourinhaË Formation consists of mostly aluvial sediments, deposited during the early rifting of the Atlantic Ocean in the Kimmeridgian and Tithonian. The stratigraphic succession shows several shifts between flood-plain mud and fluvial sands that favour preservation and fossilization of tracks. The studied track-assemblage is found preserved as natural casts on the underside of a thin bivalve-rich carbonate bed near the TithonianâKimmeridgian boundary. The diversity of the tracks from the new track assemblage is compared with similar faunas from the Upper Jurassic of Asturias, Spain and the Middle Jurassic Yorkshire Coast of England. The Portuguese record of Upper Jurassic dinosaur body fossils show close similarity to the track fauna from the LourinhaË Formation.
Abstract: THE SAUROPOD DINOSAUR TURIASAURUS RIODEVENSIS IN THE LATE
JURASSIC OF PORTUGAL
MATEUS, Octávio, New University of Lisbon (CICEGe-FCT) & Museum of Lourinhã,
Lisboa, Portugal
A partial sauropod was found in 1996 in Vale Pombas, north of Lourinhã, Central West of
Portugal, in the Lourinhã Formation, top of Amoreira Porto Novo member dated as c. 150
M.a. (Early Tithonian, Late Jurassic) and is currently housed at Museum of Lourinhã, in
Portugal. The specimen (ML368) comprises a complete tooth with root, anterior chevron
and almost complete right forelimb including partial scapula, complete coracoid, humerus,
ulna, radius, metacarpals I, III and V, phalanx, and ungual phalanx I. It can be ascribed
to Turiasaurus riodevensis, which was previously described from the Villar del Arzobispo
Formation at Riodeva (Teruel, Spain). Characters shared with T. riodevensis holotype
include: curvature and asymmetry of tooth crown, expansion of crown, outline of humerus,
medial deflection of the proximal end of humerus, shape and prominence of deltopectoral
crest, vertical ridge in the distal half of the ulna (considered as diagnostic of Turiasauria),
configuration of metacarpals, and bone proportions. It differs from T. riodevensis holotype
by the smaller size and the more rectangular ungual phalanx in lateral view. The sediments
from which the Riodeva specimen was recovered were previsouly thought to be Tithonian to
Berriasian in age. The presence of this species in Portugal, in beds confidently dated as Early
Tithonian, may allow a more precise date for the Riodeva type locality of early Tithonian in
age. The humerus of the Portuguese T. riodevensis is 152 cm long. Although shorter than the
Spanish specimen (790 mm), it represents a large individual. All adult sauropods recovered
in Portugal thus far are very large individuals: Dinheirosaurus (estimated body length is 20-
25 m), Lusotitan (humerus length estimated to be 205 cm), Lourinhasaurus (femur length:
174 cm), and Turiasaurus here reported. The lack of of small or medium adult body-size
sauropods in the Late Jurassic of Portugal, suggests browsing niches thought to be occupied
by smaller forms, could be have been available for other dinosaurs, like the long necked
stegosaur Miragaia longicollum.
Abstract: A new Late Cretaceous turtle, Angolachelys ombeu gen. et sp. nov., from the Turonian (90 Mya) of Angola, represents the oldest eucryptodire from Africa. Phylogenetic analysis recovers Angolachelys ombeu as the sister taxon of Sandownia harrisi from the Aptian of Isle of Wight, England. An unnamed turtle from the Albian Glen Rose Formation of Texas (USA) and the Kimmeridgian turtle Solnhofia parsonsi (Germany),
are successively more distant sister taxa. Bootstrap analysis suggests those four taxa together form a previously unrecognized monophyletic clade of marine turtles, herein named Angolachelonia n. clade, supported by the following synapomorphies: mandibular articulation of quadrate aligned with or posterior to the occiput, and basisphenoid not visible or visibility greatly reduced in ventral view. Basal eucryptodires and angolachelonians originated in the northern hemisphere, thus Angolachelys represents one of the first marine amniote lineages to have invaded the South Atlantic after separation of Africa and South America.
Abstract: A portion of a left humerus from the Upper Maastrichtian of Vratsa district (NW Bulgaria) is shown to be from a non-avian theropod dinosaur: this is the first record of a dinosaur from Bulgaria. We describe this bone, suggest that it most likely pertains to an ornithomimosaur, and discuss the fossil record of other similar taxa of Late Cretaceous age that have been reported from Europe. To investigate the taphonomy of this fossil, rare earth element (REE) analysis is combined with strontium (Sr) isotope data to confirm that this Bulgarian dinosaur bone was initially fossilized in a terrestrial environment, then later re-worked into late Maastrichtian marine sediments. â¡Bulgaria, Dinosauria, Late Cretaceous, Ornithomimosauria, rare earth elements, Sr isotopes, taphonomy, Theropoda.
Abstract: Stegosaurian dinosaurs have a quadrupedal stance, short forelimbs, short necks, and are generally considered to be low browsers. A new stegosaur, Miragaia longicollum gen. et sp. nov., from the Late Jurassic of Portugal, has a neck comprising at least 17 cervical vertebrae. This is eight additional cervical vertebrae when compared with the ancestral condition seen in basal ornithischians such as Scutellosaurus. Miragaia has a higher cervical count than most of the iconically long-necked sauropod dinosaurs. Long neck length has been achieved by âcervicalizationâ of anterior dorsal vertebrae and probable lengthening of centra. All these anatomical features are evolutionarily convergent with those exhibited in the necks of sauropod dinosaurs. Miragaia longicollum is based upon a partial articulated skeleton, and includes the only known cranial remains from any European stegosaur. A well-resolved phylogeny supports a new clade that unites Miragaia and Dacentrurus as the sister group to Stegosaurus; this new topology challenges the common view of Dacentrurus as a basal stegosaur.
Abstract: Thyreophoran dinosaurs have spike- and club-shaped osteoderms probably used for defensive weapons. The structural and histological variations have been little known. Here,
we provide the comparisons of the internal structures in defensive weapons of ankylosaurs and stegosaurs, using spikes of a polacanthid (Gastonia) and a nodosaurid (Edmontonia), clubs of ankylosaurids (Saichania and Ankylosauridae indet. from Canada), and spikes of stegosaurids (Stegosaurus and Dacentrurus), which sheds light on understandings of evolutionary history and functional implications of defensive weapons in thyreophorans.
In ankylosaurs, the structural and histological features of spikes and clubs are similar with those of small osteoderms in having thin compact bones, thick cancellous bones with large vascular canals, and abundant collagen fibers. A previous study demonstrated that each of three groups of ankylosaurs (polacanthid, nodosaurid, and ankylosaurid) has distinct characteristic arrangements of collagen fibers in small osteoderms. This study shows that spikes and clubs of ankylosaurs maintain the same characteristic features for each group despite of the differences in shapes and sizes. Conversely, the spike-shaped osteoderms in primitive (Dacentrurus) and derived (Stegosaurus) stegosaurids have similar structure to each other and are significantly different from the other types of stegosaur osteoderms (throat bony ossicles and plates) in having thick compact bones with a medullary cavity.
These lack abundant collagen fibers unlike ankylosaur osteoderms. The spikes of ankylosaurs and stegosaurs are similar in shape, but their structural and histological features
are different in having unique structures of collagen fibers for ankylosaurs and thick compact bones for stegosaurs, providing enough strength to have large spikes and to use them as defensive weapons. Although the shapes of ankylosaur clubs are different from spikes, the internal structures are similar, suggesting that ankylosaurs maintain similar structures despite of different shapes in osteoderms. These results indicate that ankylosaurs and stegosaurs used different strategies independently to evolve defensive weapons.
Abstract: <p>Sauropods are often considered to have very limited mobility and reduced limb flexibility, mainly due to their giant size and consequent weight. In the Upper Jurassic Lourinh&$#$227; Formation, central-west Portugal, deep vertical natural casts of sauropod manus tracks are often preserved as the infills of the original tracks. These manus tracks are vertical-walled, with marks of the striations of the skin scales, showing that the movement of the sauropod manus impacting and exiting the mud was totally vertical with no horizontal component of the stride. Some tracks are up to 66 cm deep, which is equivalent to the height of whole sauropod manus. This means that sauropods could lift their anterior feet in a complete vertical manner. Such movement is only possible if there is mobility at elbow and shoulder articulations in a higher degree than previously thought for sauropods. Our vision of sauropod limbs as inflexible columns has to be updated to a more dynamic model for limbs and body.</p>
Abstract: <p>Two techniques (stone-splitters and demolition agents) are revealed to be efficient methods for breaking large stone blocks in extreme paleontological excavation. In certain conditions – where security factors, permission issues, terrain conditions, rock properties are problematic – the traditional methods for breaking large rock blocks cannot be applied (e.g. crane trucks or explosives). Using an expansive demolition agent or stone-splitters after drilling equidistant holes not only allows a cheap, quick and safe solution but also permits precise removal of up to 9 ton blocks. Stone-splitters are a three-part tool that when inserted linearly and equidistantly along a brittle rock mass cause a precise fracture.</p>
Abstract: <p>Here we describe a new species of the mosasaurine genus Prognathodon from the Maastrichtian of Namibe, Angola, on the basis of five specimens which represent most of the cranial skeleton including the diagnostic quadrate. Phylogenetic analysis shows this new taxon, P. kianda nov. sp., to be the sister taxon to all other species of Prognathodon. It is unique amongst Prognathodon in possessing a high marginal tooth count and relatively small pterygoid teeth. The tooth morphology in the new taxon is reminiscent of some species of the genus Liodon, allowing association of Liodon-like dentition with otherwise Prognathodon-like crania, and thus resolves the long-standing question of the phylogenetic affinities of Liodon.</p>
Abstract: <p>Portugal has been providing dinosaur remains since, at least, 1863. The 18th century tiles depicting the legend of Our Lady in Cabo Espichel are probably the oldest known dinosaur track illustration. To our knowledge, the first remains found in Portugal were theropod teeth collected near Porto das Barcas (Late Jurassic of Lourinh&$#$227;) in June 20th, 1863 by the geologist Carlos Ribeiro (1813-1882). The first dinosaur paper was written by Henri Sauvage (1842-1917) published in 1896. All remains collected since 19th century were gathered in a work signed by Albert de Lapparent (1905-1975) and Georges Zbyszewski (1909-1999 ) titled Les Dinosauriens du Portugal (1957) that was a significant milestone in the Portuguese dinosaur paleontology and gives the state-of-the-art by the time. Several dinosaurs are named, described, depicted and mapped in that monograph. The first track record is given by Jacinto Pedro Gomes (1844-1916) in 1916. Concerning the non-scientific literature referring to dinosaurs, in 1884 the newspaper Occidente reports the Bernissart findings in Belgium. In the 1959 occurs the first visit to Portugal of Walter K&$#$252;hne (1911-1991) from the Free University of Berlin. Further visits and work granted the access to the Guimarota Mine and other Late Jurassic deposits in the 1960’s, 70’s and 80’s with a high number of publications. In the 1980’s and early 1990’s starts a progressive era for dinosaur paleontology in Portugal with the works of Peter Galton, Miguel Telles Antunes, the Natural History Museum, the Museum of Lourinh&$#$227; and the New University of Lisbon, Oliver Rauhut, and others.</p>
Abstract: <p>For historical and geological reasons the dinosaurian fossil record from central Europe is little known. Here we describe and interpret a portion of a left humerus from the Upper Maastrichtian of Vratsa district in north-western Bulgaria. This bone is the first known record of a dinosaur from Bulgaria; it is certainly a theropod, probably an ornithomimosaur. We discuss the fossil record of other similar fossils of theropod dinosaurs, in particular other problematic remains from the Maastrichtian of Belgium. Rare Earth Element (REE) analysis combined with strontium (Sr) isotope data demonstrate that the Bulgarian dinosaur was initially fossilised in a terrestrial environment and then later re-worked into Late Maastrichtian marine sediments.</p>
Abstract: <p>Thyreophoran dinosaurs have spike- and club-shaped osteoderms probably used for defensive weapons. The structural and histological variations have been little known. Here, we provide the comparisons of the internal structures in defensive weapons of ankylosaurs and stegosaurs, using spikes of a polacanthid (Gastonia) and a nodosaurid (Edmontonia), clubs of ankylosaurids (Saichania and Ankylosauridae indet. from Canada), and spikes of stegosaurids (Stegosaurus and Dacentrurus), which sheds light on understandings of evolutionary history and functional implications of defensive weapons in thyreophorans. In ankylosaurs, the structural and histological features of spikes and clubs are similar with those of small osteoderms in having thin compact bones, thick cancellous bones with large vascular canals, and abundant collagen fibers. A previous study demonstrated that each of three groups of ankylosaurs (polacanthid, nodosaurid, and ankylosaurid) has distinct characteristic arrangements of collagen fibers in small osteoderms. This study shows that spikes and clubs of ankylosaurs maintain the same characteristic features for each group despite of the differences in shapes and sizes. Conversely, the spike-shaped osteoderms in primitive (Dacentrurus) and derived (Stegosaurus) stegosaurids have similar structure to each other and are significantly different from the other types of stegosaur osteoderms (throat bony ossicles and plates) in having thick compact bones with a medullary cavity. These lack abundant collagen fibers unlike ankylosaur osteoderms. The spikes of ankylosaurs and stegosaurs are similar in shape, but their structural and histological features are different in having unique structures of collagen fibers for ankylosaurs and thick compact bones for stegosaurs, providing enough strength to have large spikes and to use them as defensive weapons. Although the shapes of ankylosaur clubs are different from spikes, the internal structures are similar, suggesting that ankylosaurs maintain similar structures despite of different shapes in osteoderms. These results indicate that ankylosaurs and stegosaurs used different strategies independently to evolve defensive weapons.</p>
Abstract: <p>Dinosaurs and other fossils have been artificially enhanced, or totally forged, to increase their commercial value. The most problematic forgeries to detect are based on original fossils that are artificially assembled. Several techniques are suggested for detecting hoaxes: detailed visual examination, chemical analysis, Xray or CT-scan, and ultraviolet light. It is recommended that museums and paleontological researchers do not purchase and/or trade fossils lacking clear provenience information. Exceptions to that general rule should be closely examined using techniques described herein.</p>
Abstract: Two techniques (stone-splitters and demolition agents) are revealed to be efficient methods for breaking
large stone blocks in extreme paleontological excavation. In certain conditions â where security factors,
permission issues, terrain conditions, rock properties are problematic â the traditional methods for breaking
large rock blocks cannot be applied (e.g. crane trucks or explosives). Using an expansive demolition agent
or stone-splitters after drilling equidistant holes not only allows a cheap, quick and safe solution but also
permits precise removal of up to 9 ton blocks.
Stone-splitters are a three-part tool that when inserted linearly and equidistantly along a brittle rock mass
cause a precise fracture.
Abstract: Dinosaurs and other fossils have been artificially enhanced, or totally forged, to increase their commercial
value. The most problematic forgeries to detect are based on original fossils that are artificially assembled.
Several techniques are suggested for detecting hoaxes: detailed visual examination, chemical analysis, Xray
or CT-scan, and ultraviolet light.
It is recommended that museums and paleontological researchers do not purchase and/or trade fossils
lacking clear provenience information. Exceptions to that general rule should be closely examined using
techniques described herein.
Abstract: Recent fieldwork in the Namibe province in southern Angola yielded cranial and post- cranial elements of at least two individuals of the rare and enigmatic mosasaur Halisaurus from a single small excavation. The genus Halisaurus is unique in retaining a primitive configuration of the temporal arcade, specifically a broad, vertically oriented contact between the parietal and the supratemporal. The supratemporal is broadly sutured to the opisthotic and prootic, unlike the condition in varanoids in which the simple lunate element lies between the parietal ramus and the squamosal and does not form a sutural contact with the opisthotic or prootic, but as in other halisaurines retains a plesiomorphic, vertically oriented contact with the parietal rami. The squamosal is lightly built and broadly arched as in Varanus. Comparison with known halisaurines indicates the new material is referable to the species Halisaurus arambourgi. The locality that yielded the new specimens has also yielded a large number of isolated teeth, bones, articulated, and associated skeletons of Mosasaurus,Prognathodon, Globidens, and Plioplatecarpus, which with Halisaurus comprise a mosasaur assemblage most similar to that reported from the Maastrichtian of Morocco.
Abstract: The record of ornithischian dinosaurs from Portugal is substantial but incomplete in terms of our understanding of taxonomic composition and details of the anatomy of many forms. New data and reinterpretation of these forms are provided. The basal thyreophoran from the Lower Jurassic (the nomen dubium âLusitanosaurus liasicusâ) is the most primitive dinosaur from Iberia. Concerning the Late Jurassic, new material from the Lourinhã Formation (Kimmeridgian/Tithonian) referable to the stegosaur Dacentrurus provides additional information on the systematic position and osteology. The new material shows two rows of paired triangular plates, with a notch in the ante- rior rim. A maxillary of an ankylosaur from the Vale Frades (Lourinhã Fm.) is here reported, but cannot be referable to Dracopelta, the only ankylosaur genus currently known from Portugal. The ornithopod Alocodon kuehnei reported as Middle Jurassic (Callovian) is probably Oxfordian in age. A right dentary (ML768 from Zimbral) from the Lourinhã Formation, Kimmeridgian/Tithonian, and shares affinities with Dryosaurus but possesses more denticulation and no secondary ridges, suggesting the occurrence of a new or unreported species for the Late Jurassic of Portugal, which is here tentatively ascribed to aff. Dryosaurus sp. In summary, the Late Jurassic ornithis- chians species/genera from Portugal include Dacentrurus armatus, Stegosaurus cf. ungu- latus, Dracopelta zbyszewskii, Phyllodon henkeli, Hypsilophodon sp., Alocodon kuehnei, Trimucrodon cuneatus, aff. Dryosaurus andDraconyx loureiroi. The Lower Cretaceous (Hauterivian / Barremian) of Praia das Aguncheiras, in Cabo Espichel, provided a par- tial left maxillary (CPGP.1.99.7) of a basal iguanodontian that shows affinities with Camptosaurus, and is tentatively assigned to this genus. The maxillary teeth denticles differ from Iguanodon or other Iguanodontoidea because not show mammillations. More material is necessary to validate but, to be true, that would confirm the presence of this genus in the lower Cretaceous. The Iguanodon has been reported in the Lower Cretaceous of Cabo Espichel.
Abstract: The presence of marine reptiles from Portugal was reported as early as 1897. Ichthyosaurs have been reported from the Lower and Middle Jurassic (Sinemurian to the Aalenian).Ichthyosaurus sp., was recognized from Cádima, Murtede, Cantanhede and Figueira da Foz, Ichthyosaurus intermedius was reported from São Pedro de Muel (Lower Toarcian), Alvaiázere, Casal Comba, and Praia da Nossa Senhora da Vitória (Sinemurian) and Stenopterygius aff. uniter is present in Alhadas, Pentalheira, Praia de Nossa Senhora da Vitória and Tomar (Aalenian). The genus Stenopterygius was also reported in Condeixa and Tomar. In addition, we report two new ichthyosaur speci- mens from the Pliensbachian of Agua de Madeiros (São Pedro de Muel), one from the Domerian preserving a forelimb, vertebrae and teeth and a juvenile specimen dated as Carixian that preserves the cranial material and dorsal vertebrae and ribs. Plesiosaur material includes a partial skull of Plesiosaurus sp. and part of jaw ascribed to aff. Plesiosaurus, both from the Toarcian of Alhadas, near Figueira da Foz and an unpub- lished tooth from the Middle Cretaceous of São Pedro do Estoril. The Kimmeridgian/Tithonian of Lourinhã Formation yielded a possible plesiosaur vertebra (ML813). An isolated vertebra from the Late Cretaceous Cenomanian of Alcântara is assigned to âCimoliasaurusâ. Mosasaurs are known from two teeth from the Late Cretaceous of Aveiro. One was ascribed to the genus Mosasaurus and the relatively large size may support that referral; however, it is difficult to assign teeth to genus but based on its general form and possession of smooth enamel surface it is possible to conserva- tively refer the specimen to the subfamily Mosasaurinae. Marine crocodiles
Abstract: <p>Although occurrences of marine reptiles have been previously reported from Angola, with the exception of two Turonian taxa, these reports were based largely on isolated teeth. Fieldwork in 2005 and 2006 yielded well-preserved remains of marine reptiles including plesiosaurs, turtles, and mosasaurs. The mosasaurs discussed here were recovered from two field areas: Turonian sediments at Iembe along the north coast and Maastrichtian sediments at Bentiaba on the south coast. The Turonian section near Iembe produced at least two new specimens of Angolasaurus bocagei and one fragmentary specimen of Tylosaurus iembeensis. One of the Angolasaurus specimens is represented by a well preserved, complete and articulated skull and partial postcrania, including portions of the forelimbs and pectoral girdle. The preservation of material from the Bentiaba locality is remarkable due to the grain support of the entombing sandstone, which preserves fine anatomical details with little apparent crushing, and in the number of articulated, semi-articulated, and associated skeletons. Identifications from the field and preliminary preparation show the Bentiaba mosasaur fauna is represented by at least five genera including Mosasaurus, Prognathodon, Globidens, Plioplatecarpus and Halisaurus. Collectively, these new specimens greatly expand our knowledge of the anatomy and systematics of Angolan mosasaurs.</p>
Abstract: <p>Late Jurassic theropod dinosaurs have been known in Portugal since 1863 but only now are they being fully understood, with the recognition of genera such as Allosaurus, Aviatyrannis, Ceratosaurus, Lourinhanosaurus, and Torvosaurus from the Lourinhã and Alcoba\c ca Formations (Kimmeridgian/Tithonian). Ceratosaurus dentisulcatus can now be reported from Portugal. It represents the only occurrence of this species outside the Morrison Formation.<br /> New cranial elements confirm the presence of Torvosaurus tanneri, in Portugal. Torvosaurus was the largest Late Jurassic land carnivore. New postcranial and cranial elements allow the erection of a new species from Portugal, Allosaurus europaeus n.sp. The theropod assemblage of Portugal is similar to that of the Morrison Formation. </p>
Abstract: Sauropod dinosaurs were the largest animals ever to inhabit the land, with truly gigantic forms in at least three lineages1â3. Small species with an adult body mass less than five tonnes are very rare4,5, and small sauropod bones generally represent juveniles. Here we describe a new diminutive species of basal macronarian sauropod, Europasaurus holgeri gen. et sp. nov., and on the basis of bone histology we show it to have been a dwarf species. The fossils, including excellent skull material, come from Kimmeridgian
marine beds of northern Germany6,7, and record more than 11 individuals of sauropods 1.7 to 6.2m in total body length. Morphological overlap between partial skeletons and isolated bones links all material to the same new taxon. Cortical histology of femora and tibiae indicates that size differences within the specimens are due to different ontogenetic stages, from juveniles to fully grown individuals. The little dinosaurs must have lived on one of the large islands around the Lower Saxony basin8. Comparison with the long-bone histology of large-bodied sauropods suggests that the island dwarf species evolved through a decrease in growth rate from its larger ancestor.
Notes: See also Supplementary Information available at http://omateus.googlepages.com/Sander_et_al_2006_Europasaurus_Natur.pdf
Abstract: Sauropods were the largest animals ever to walk the earth, and evolved several specializations in their limbs in order to support their body mass. Their legs became columnar and their manual digits became reduced and encapsulated in tissue to form a single weight-bearing unit in the derived sauropods. A new three-dimensionally preserved cast of a sauropod manus, found in the Upper Jurassic Lourinhã Formation, Portugal, demonstrates not only the shape, but also the actual movements of the sauropod manus during the stride. The manus cast is 32 cm deep, and show the manus to be hoof-shaped and lacking any impressions of individual digits, except for digit I, the pollex. Well preserved striations from skin on the sides of the cast show that the manus was covered in rough, tubercular skin. The width of the manus cast is consistent from top to bottom, demonstrating that the manus was brought down and lifted vertically before any parasaggital movement of the upper
limb took place.
Notes: See also:
MATEUS, O. & MILÃN, J., 2010. A diverse Upper Jurassic dinosaur ichnofauna from central-west Portugal. Lethaia, 43(2), 245â257.
Mateus, O. & Milà n, J., 2008. Ichnological evidence for giant ornithopod dinosaurs in the Upper Jurassic Lourinh\ a Formation, Portugal. Oryctos, 8, 47â52.
Abstract: <p>Sauropods were the largest animals ever to walk the earth, and evolved several specializations in their limbs in order to support their body mass. Their legs became columnar and their manual digits became reduced and encapsulated in tissue to form a single weight-bearing unit in the derived sauropods. A new three-dimensionally preserved cast of a sauropod manus, found in the Upper Jurassic Lourinh&$#$227; Formation, Portugal, demonstrates not only the shape, but also the actual movements of the sauropod manus during the stride. The manus cast is 32 cm deep, and show the manus to be hoof-shaped and lacking any impressions of individual digits, except for digit I, the pollex. Well preserved striations from skin on the sides of the cast show that the manus was covered in rough, tubercular skin. The width of the manus cast is consistent from top to bottom, demonstrating that the manus was brought down and lifted vertically before any parasaggital movement of the upper limb took place.</p>
Notes: <p>See also: MATEUS, O. &$#$38; MIL&$#$192;N, J., 2010. A diverse Upper Jurassic dinosaur ichnofauna from central-west Portugal. Lethaia, 43(2), 245–257. Mateus, O. &$#$38; Mil&$#$224;n, J., 2008. Ichnological evidence for giant ornithopod dinosaurs in the Upper Jurassic Lourinh\ a Formation, Portugal. Oryctos, 8, 47–52.</p>
Abstract: <p>The Late Jurassic Lourinhã Formation contains a diverse dinosaur fauna comprising theropods, sauropods, stegosaurs, ankylosaurs and several genera of ornithopods.<br /> The sedimentology in the area favours preservation of footprints, and footprints from most of the dinosaurs represented by skeletal remains are present in the area. During fieldwork in the summer of 2003 a new, large, tridactyl footprint was found at the beach of Vale Frades, approximately 6 km north of Lourinhã, Portugal. The footprint was found together with a stegosaur footprint on a clay bed exposed within the tidal zone. The footprints were preserved</p> <p>as sandstone casts standing on a pedestal of clay. This unusual type of preservation is the result of the footprints having first been emplaced in clay, and then filled with sand. During the present day erosion from the sea, the harder sandstone cast of the footprints protects the subjacent clay layers from erosion. Owing to the immediate danger of erosion of, the footprint was collected and is now on display at Museu da Lourinhã (ML 1000). The footprint is 70 cm long and 69 cm wide, the toes are short and broad, with indications of short blunt claws. The</p> <p>divarication angle between the outer digits is close to 90 degrees. The dimensions and general</p> <p>morphology of the footprint identifies it as deriving from an ornithopod dinosaur with an estimated hip height of 4.13 metres. Although very large ornithopods are known from the Cretaceous, the largest known Jurassic ornithopod is Camptosaurus from USA, and the largest known from Portugal is the camptosaurid Draconyx loureiroi. Neither of these reached the body size suggested by the new footprint. So far the footprint described herein is s the only evidence for a Jurassic ornithopod of that size.</p>
Abstract: <p>Sedimentological features of the Paimogo site, 6 km NNW of Lourinh&$#$227;, western central Portugal are presented. More than one hundred theropod dinosaur eggs (some containing embryo bones) ascribed to Lourinhanosaurus antunesi Mateus 1998, three crocodilian eggs and some other fossils were found at the 32 m2 excavated area of the egg-bearing horizon (Mateus et al., 1998). The stratigraphic position of the site is the Praia Azul member (Lourinh&$#$227; Formation), roughly corresponding to the Kimmeridgian-Tithonian boundary or, more likely lowermost Tithonian. The maximum flooding surface of the basinal transgressive event where the horizon is located corresponds to the base of the H depositional sequence defined by Pena dos Reis et al. (2000) and probably correlates to the base of sequence Ti1 identified within western European basins (Jacquin et al., 1998), dated as 150 Ma. Possibly during the normal river discharge, the theropods congregated in nesting colonies at the backswamp of an extensive flood plain with small meandering channels and freshwater ponds. There are no evidences that the nest was dug or the eggs buried. The eggs have probably been laid on a flat, shaded, muddy area near the bank of a large pond. It is probable that the eggs have not been actively incubated. The larger number of eggs suggest that they were laid near simultaneously by, at least, six females. The fossil record shows that crocodilians, mammals, gastropods and fish were also present. A flood event occurred when theropod embryos had attained a late stade of ontogenetic development, probably just before hatching. The overflow from a nearby channel flooded the plain, including the area where the eggs had been laid. The sheet flood flowing over the nest resulted into the scattering and breaking up of some dinosaur eggs. Eggshell and embryos skeletal parts fragments were displaced to an adjacent area where, due to hydrodynamic decline, the flow submerged other clutches and moderately dragged their eggs. The flooding caused the drowning of the embryos and covered the eggs with fine-grained sediment, hiding them from predators and scavengers. Hydrodynamic interpretation of the arrangement of the theropod eggs and egg-fragments suggests that the flow came from the NW. When the floodwaters receded, the fine-grained deposits became exposed to subaerial weathering. Although the sediment surface was often wet and small bodies of standing water may still have existed, the sediments were oxidized and plant remains have consequently been destroyed. Some carbonate cementation and redenning resulted from pedogenesis under alternating dry and moist conditions, in a semiarid/ sub-tropical climate under seasonal changing, contrasting conditions. The thick, stratigraphically above and below the nesting horizon mudrocks indicate a long persistence of periodic flooding, alternating with pedogenesis. During the early stages of diagenesis, vertical pressure crushed the eggs. Silt penetration into the inner part of each egg inhibited later flattening during the burial process.</p>
Abstract: A synthesis on the state of art on dinosaur knowledge in Portugal is presented. The following genera have been recognized: Ceratosaurus, Torvosaurus, Lourinhanosaurus, Allosaurus, cf. Compsognathus, Stokesosaurus, cf. Richardoestesia, cf. Archaeopteryx, Euronychodon, cf. Paronychodon, Dinheirosaurus, Lourinhasaurus, Lusotitan, cf. Pleurocoelus, Lusitanosaurus, Dacentrurus, Dracopelta, Phyllodon, Hypsilophodon, Alocodon, Trimucrodon, Draconyx, Iguanodon, and Taveirosaurus. Most are from Late Jurassic localities at the Lourinhã area and Guimarota. A new genus, Lusotitan, is here raised to include the Late Jurassic âÂÂBrachiosaurusâ atalaiensis. Lower Cretaceous until Cenomanian material is scarce, except for dinosaur footprints. An interesting Late-Cretaceous, mostly small dinosaur association has been collected between Aveiro and Taveiro.
Notes: See citations: http://scholar.google.com/scholar?cites=6166201060755301358&as_sdt=2005&sciodt=2000&hl=en
Sander et al (2006), Rauhut (2005)(2006)(2008), Escaso et al (2007), Benson (2008), Mateus et al (2009), Martin et al (2005), Wright & Curry Rogers (2005), Canudo et al (2006), Mateus & Milà n (2008)(2010), Ortega et al (2006), Taylor (2009), Buffetaut (2007), Royo-Torres (2006), Royo-Torres et al (2009), Ruiz-Omeñaca et al (2005), ortega et al (2008), Balbino (2003), Soto & Perea (2008), Canudo (2009), You & Li (2009), Noto et al (2010), Schneider (2010), Mannion (2010), Rodrigues (2008), Araújo et al (2009)...... and others.
Abstract: <p>A synthesis on the state of art on dinosaur knowledge in Portugal is presented. The following genera have been recognized: Ceratosaurus, Torvosaurus, Lourinhanosaurus, Allosaurus, cf. Compsognathus, Stokesosaurus, cf. Richardoestesia, cf. Archaeopteryx, Euronychodon, cf. Paronychodon, Dinheirosaurus, Lourinhasaurus, Lusotitan, cf. Pleurocoelus, Lusitanosaurus, Dacentrurus, Dracopelta, Phyllodon, Hypsilophodon, Alocodon, Trimucrodon, Draconyx, Iguanodon, and Taveirosaurus. Most are from Late Jurassic localities at the Lourinh&$#$227; area and Guimarota. A new genus, Lusotitan, is here raised to include the Late Jurassic &$#$226;ÃÂÃÂBrachiosaurus&$#$226;ÃÂÃÂ atalaiensis. Lower Cretaceous until Cenomanian material is scarce, except for dinosaur footprints. An interesting Late-Cretaceous, mostly small dinosaur association has been collected between Aveiro and Taveiro.</p>
Notes: <p>See citations: <a href="http://scholar.google.com/scholar?cites=6166201060755301358&as_sdt=2005&sciodt=2000&hl=en">http://scholar.google.com/scholar?cites=6166201060755301358&$#$38;as_sdt=2005&$#$38;sciodt=2000&$#$38;hl=en</a> Sander et al (2006), Rauhut (2005)(2006)(2008), Escaso et al (2007), Benson (2008), Mateus et al (2009), Martin et al (2005), Wright &$#$38; Curry Rogers (2005), Canudo et al (2006), Mateus &$#$38; Mil&$#$224;n (2008)(2010), Ortega et al (2006), Taylor (2009), Buffetaut (2007), Royo-Torres (2006), Royo-Torres et al (2009), Ruiz-Ome&$#$241;aca et al (2005), ortega et al (2008), Balbino (2003), Soto &$#$38; Perea (2008), Canudo (2009), You &$#$38; Li (2009), Noto et al (2010), Schneider (2010), Mannion (2010), Rodrigues (2008), Ara&$#$250;jo et al (2009)...... and others.</p>
Abstract: Remains of dinosaurian embryos, hatchlings and early juveniles are currently the subject of increasing interest, as new discoveries and techniques now allow to analyse
palaeobiological subjects such as growth and life history strategies of dinosaurs. So far, available âembryonicâ material mainly involved Ornithopods and some Theropods of Upper Cretaceous age. We describe here the histology of several bones (vertebrae, limb bones) from the tiny but exceptionally well preserved in ovo remains of Upper Jurassic Theropod dinosaurs from the Paimogo locality near Lourinhã (Portugal). This Jurassic material allows to extend in time and to considerably supplement in great details our knowledge of early phases of growth in diameter and in length of endoskeletal bones of various shape, as well as shape modelling among carnivorous dinosaurs. Endochondral ossiï¬cation in both short and long bones involves extensive pads of calciï¬ed cartilages permeated by marrow buds. We discuss the likely occurrence of genuine cartilage canals in dinosaurs and of an avian-like âmedullary cartilaginous coneâ in Theropods. Patterns of periosteal ossiï¬cation suggest high initial growth rates (20 µm·dayâ1 or more), at once modulated by precise and locally speciï¬c changes in rates of new bone deposition. The resulting very precise shape modelling appears to start early and to involve at once some biomechanical components.
Abstract: <p>Remains of dinosaurian embryos, hatchlings and early juveniles are currently the subject of increasing interest, as new discoveries and techniques now allow to analyse palaeobiological subjects such as growth and life history strategies of dinosaurs. So far, available ‘embryonic’ material mainly involved Ornithopods and some Theropods of Upper Cretaceous age. We describe here the histology of several bones (vertebrae, limb bones) from the tiny but exceptionally well preserved in ovo remains of Upper Jurassic Theropod dinosaurs from the Paimogo locality near Lourinh&$#$227; (Portugal). This Jurassic material allows to extend in time and to considerably supplement in great details our knowledge of early phases of growth in diameter and in length of endoskeletal bones of various shape, as well as shape modelling among carnivorous dinosaurs. Endochondral ossification in both short and long bones involves extensive pads of calcified cartilages permeated by marrow buds. We discuss the likely occurrence of genuine cartilage canals in dinosaurs and of an avian-like ‘medullary cartilaginous cone’ in Theropods. Patterns of periosteal ossification suggest high initial growth rates (20 &$#$181;m&$#$183;day−1 or more), at once modulated by precise and locally specific changes in rates of new bone deposition. The resulting very precise shape modelling appears to start early and to involve at once some biomechanical components.</p>
Abstract: <p>Presacral vertebrae of a new Diplodocidae from the Late Jurassic Amoreira-Porto Novo Formation of Lourinh&$#$227;, Portugal are described and figured. Dinheirosaurus lourinhanensis gen. et sp. is diagnosed by well developed accessory articulations derived from the hyposphene, exposed in lateral view; and by the smaller dorsoventral length of the lower section of the neural arch. It is considered that the organization of the dorsal neural arch of Dinheirosaurus is more derived than in Diplodocus, except in the dorsoventral development of the lower portion of it, which is higher (more derived) in the latter. Possibly the isolated geography of Portugal in the Late Jurassic gave rise to the distinct characters of this new genus.</p>
Abstract: <p>The partly-articulated postcranial remains of two sauropod skeletons recently found in Tang Vay (Savannakhet Province, Laos) are assigned to the species Tangvayosaurus hoffeti (nov. gen., nov. sp.). The derived characters present in the new material confirm the presence of titanosaurs in South East Asia at the end of the Early Cretaceous, but are not consistent with its placement within Titanosaurus genus as first done by Hoffet in 1942. All of the material relative to this species is therefore referred to a new genus: Tangvayosaurus. Tangvayosaurus and the Thai genus Phuwiangosaurus have strong affinities and are considered as primitive titanosaurs. Les restes postcr&$#$195;&$#$162;niens, partiellement articul&$#$195;&$#$169;s, de deux squelettes de sauropodes r&$#$195;&$#$169;cemment d&$#$195;&$#$169;couverts &$#$195;&$#$160; Tang Vay (Province de Savannakhet, Laos) sont assign&$#$195;&$#$169;s &$#$195;&$#$160; l’esp&$#$195;šce Tangvayosaurus hoffeti (nov.gen., nov. sp.). Les caract&$#$195;šres d&$#$195;&$#$169;riv&$#$195;&$#$169;s port&$#$195;&$#$169;s par le nouveau mat&$#$195;&$#$169;riel confirment la pr&$#$195;&$#$169;sence de titanosaures en Asie du Sud-Est &$#$195;&$#$160; la fin du Cr&$#$195;&$#$169;tac&$#$195;&$#$169; inf&$#$195;&$#$169;rieur, mais ne justifient pas son rattachement au genre Titanosaurus, comme le fit originellement Hoffet en 1942. L’ensemble du mat&$#$195;&$#$169;riel relatif &$#$195;&$#$160; cette esp&$#$195;šce est donc attribu&$#$195;&$#$169; &$#$195;&$#$160; un nouveau genre : Tangvayosaurus, n.g. Tangvayosaurus et le genre tha&$#$195;&$#$175;landais Phuwian- gosaurus pr&$#$195;&$#$169;sentent de fortes affinit&$#$195;&$#$169;s et sont consid&$#$195;&$#$169;r&$#$195;&$#$169;s comme des titanosaures primitifs. Les restes postcr&$#$195;&$#$162;niens, partiellement articul&$#$195;&$#$169;s, de deux squelettes de sauropodes r&$#$195;&$#$169;cemment d&$#$195;&$#$169;couverts &$#$195;&$#$160; Tang Vay (Province de Savannakhet, Laos) sont assign&$#$195;&$#$169;s &$#$195;&$#$160; l’esp&$#$195;šce Tangvayosaurus hoffeti (nov.gen., nov. sp.). Les caract&$#$195;šres d&$#$195;&$#$169;riv&$#$195;&$#$169;s port&$#$195;&$#$169;s par le nouveau mat&$#$195;&$#$169;riel confirment la pr&$#$195;&$#$169;sence de titanosaures en Asie du Sud-Est &$#$195;&$#$160; la fin du Cr&$#$195;&$#$169;tac&$#$195;&$#$169; inf&$#$195;&$#$169;rieur, mais ne justifient pas son rattachement au genre Titanosaurus, comme le fit originellement Hoffet en 1942. L’ensemble du mat&$#$195;&$#$169;riel relatif &$#$195;&$#$160; cette esp&$#$195;šce est donc attribu&$#$195;&$#$169; &$#$195;&$#$160; un nouveau genre : Tangvayosaurus, n.g. Tangvayosaurus et le genre tha&$#$195;&$#$175;landais Phuwian- gosaurus pr&$#$195;&$#$169;sentent de fortes affinit&$#$195;&$#$169;s et sont consid&$#$195;&$#$169;r&$#$195;&$#$169;s comme des titanosaures primitifs. en: Aptian; Albian; Laos; Gr&$#$195;šs sup&$#$195;&$#$169;rieurs; Vertebrata; Dinosauria; Sauropoda; Titanosauria Author Keywords: Aptien; Albien; Laos; Gr&$#$195;šs sup&$#$195;&$#$169;rieurs; Vertebrata; Dinosauria; Sauropoda; Titanosauria</p>
Abstract: Presacral vertebrae of a new Diplodocidae from the Late Jurassic Amoreira-Porto Novo Formation of Lourinhã, Portugal are described and figured.
Dinheirosaurus lourinhanensis gen. et sp. is diagnosed by well developed accessory articulations derived from the hyposphene, exposed in lateral view; and by the smaller dorsoventral length of the lower section of the neural arch. It is considered that the organization of the dorsal neural arch of Dinheirosaurus is more derived than in Diplodocus, except in the dorsoventral development of the lower portion of it, which is higher (more derived) in the latter. Possibly the isolated geography of
Portugal in the Late Jurassic gave rise to the distinct characters of this new genus.
Abstract: <p>Several well preserved clutches of dinosaurs have been discovered in the upper Kimmeridgian/Tithonian of Lourinh&$#$227; (Estramadur Province, Portugal). Some eggs of one clutch contained embryo elements of a theropod dinosaur. The egg-shell resembles that of eggs which have been discovered in the Upper Jurassic of Colorado</p>
Notes: <p>Cited by many authors including: Bever &$#$38; Norrell (2009) The Perinate Skull of Byronosaurus (Troodontidae) with Observations on the Cranial Ontogeny of Paravian Theropods. American Museum Novitates. See citations here: <a href="http://scholar.google.com/scholar?cites=11785323677978161519&as_sdt=2005&sciodt=2000&hl=en">http://scholar.google.com/scholar?cites=11785323677978161519&$#$38;as_sdt=2005&$#$38;sciodt=2000&$#$38;hl=en</a></p>
Abstract: Several well preserved clutches of dinosaurs have been discovered in the upper Kimmeridgian/Tithonian of Lourinhã (Estramadur Province, Portugal). Some eggs of one clutch contained embryo elements of a theropod dinosaur. The egg-shell resembles that of eggs which have been discovered in the Upper Jurassic of Colorado
Notes: Cited by many authors including:
Bever & Norrell (2009) The Perinate Skull of Byronosaurus (Troodontidae) with Observations on the Cranial Ontogeny of Paravian Theropods. American Museum Novitates.
See citations here: http://scholar.google.com/scholar?cites=11785323677978161519&as_sdt=2005&sciodt=2000&hl=en
Abstract: <p>Abstract: The paleontological collections of the Museum of Lourinhã, in Portugal, has a rich paleontological collection, particularly of Late Jurassic dinosaurs of the Lourinhã Formation (Kimmeridgian-Tithonian). Most salient highlights comprehend the following dinosaur holotype specimens: stegosaur Miragaia longicollum, theropod Lourinhanosaurus antunesi, sauropod Dinheirosaurus lourinhanensis, ornithopod Draconyx loureiroi, theropod Allosaurus europaeus, and, a mammal, Kuehneodon hahni. Other dinosaur specimens are referred including the nest and eggs and embryos of Lourinhanosaurus. Portugal is very productive in Late Jurassic vertebrates, being the seventh country bearing more dinosaur taxa.</p>
Abstract: <p>Portugal is ranked within the ten countries with more dinosaur taxa and the Lourinḥ Formation is known<br /> by the Late Jurassic findings of dinosaurs and other fossils. Often, studies of the external morphological<br /> characteristics of the fossils are not sufficient and, observations of internal structures, using non-<br /> destructive techniques, are required. The fossils here presented belong to the Museum da Lourinḥ<br /> (Portugal) and comprise a lower jaw of a basal crocodilian (possibly a Tomistomidae), eggshells and<br /> several vertebrae from the exceptionally well preserved in ovo remains of Late Jurassic theropod dinosaur<br /> Lourinhanosaurus. Neutron Tomography (NT) experiments with this material has been carried out at the<br /> Geesthacht Neutron Facility in Germany. Additionally, eggshell fragments and several vertebrae have<br /> been studied by Synchrotron-Radiation based Micro-Computed Tomography (SŔCT) at the HARWI II and<br /> BW2 beamlines, respectively. These beamlines are operated by the Helmholtz-Zentrum Geesthacht at the<br /> storage ring DORIS III at the Deutsches Elektronen\textendashSynchrotron DESY in Hamburg, Germany. In both cases<br /> (NT and SŔCT) complete 3D recordings have been obtained using a non-destructive procedure. The high-<br /> quality tomographic datasets can be effectively studied through interactive digital visualization. Hence,<br /> these visualization methods provide precious information about the 3D internal micro morphology of<br /> fossils, like the network of the eggshell pores, often invisible in more traditional techniques, and provide a<br /> direct window into the evolutionary history of organisms.</p>
Abstract: Africa is the only continent that now straddles arid zones located beneath the descending limbs of both the northern and southern Hadley cells, and it has done so since it became a distinct continent in the Early Cretaceous. Since that time, Africa has drifted tectonically some 12 degrees north and rotated approximately 45 degrees counterclockwise. This changing latitudinal setting and position of the landmass under the relatively stable Hadley Cells is manifested as southward migration of climatic zones over the past 132 million years. Data from kerogen, X-ray diffraction analysis of sedimentary matrix, carbon isotopes from shell samples and tooth enamel,new 40Ar/39Ar radiometric dates, pollen and plant macrofossils, and fossil vertebrates indicate a productive upwelling system adjacent to a coastal desert since the opening of the South Atlantic Ocean; however, the position of the coastal desert has migrated southward as Africa drifted north, resulting in today's Skeleton Coast and Benguela Current. This migration has had a profound effect on the placement of the West African coast relative to areas of high marine productivity and resulting extensive hydrocarbon deposits, on the placement of arid zones relative to the continent especially the Skeleton Coast desert, on the climatic history of the Congo Basin (which shows a Late Cretaceous decrease in aridity based on the relative abundance of analcime in the Samba core), and in reducing the southern temperate region of Africa from 17% of continental area during the Cretaceous to 2% today. We show here that these related geographic and environmental changes drove ecological and evolutionary adjustments in southern African floras and faunas, specifically with respect to the distribution of anthropoid primates, the occurrence of modern relicts such as the gnetalean Welwitschia mirabilis, endemism as in the case of ice plants, and mammalian adaption to an open environment as in springhares. Africa's tectonic drift through climate zones has been a first-order environmental determinant since the Early Cretaceous.
Abstract: Studies of carbonate, bulk organic, and compound-specific stable isotopes of carbon have shown that the Triassic-Jurassic boundary interval (including the end-Triassic mass extinction) displays major, global perturbations to the carbon cycle. These records are instrumental not only in reconstructing environmental change, as they are thought to reflect ecosystem instability and changing atmospheric gas inventories, but, due to their global nature, can be useful tools for stratigraphic correlation. The Algarve Basin, a deformed, extensional basin in the south of Portugal, has potential for yielding insight into the dramatic paleoenvironmental and faunal changes that occurred during the latest Triassic through earliest Jurassic. During this time interval, the basin records an evolution from continental to marginal marine sediments that are interbedded with radioisotopically dated Central Atlantic Magmatic Province (CAMP) basalts, thought to be a major causative agent in the end-Triassic mass extinction. Recent field excavations in the Algarve Basin have documented terrestrial vertebrate remains at multiple horizons, including a rich bone bed densely packed with well-preserved remains of large stereospondyl temnospondyls (skull length up to ~1 meter) positioned close to the Triassic-Jurassic boundary. These stereospondyls may represent some of the latest surviving members of their groups in Europe, and occur in a time interval in which stereospondyl material is scarce and represented primarily by isolated and fragmentary material. Unfortunately, the paleoenvironmental and chronologic framework of the Algarve Basin is not well constrained, despite its importance as a critical record of this time in Earth history. We present a preliminary bulk organic carbon isotope record of early Mesozoic rift-basin sediments from the Algarve Basin. This record exhibits significant variability, but appears to record a trend towards more negative values at the top of the section, though this needs better constraint with further sampling. Although the potential for changes in the source of organic material can be expected to have an effect on the overall signal, the presence of depleted δ13C values in proximity to CAMP basalts relative to stratigraphically lower sections points to the potential for identifying key negative excursions associated with Triassic-Jurassic boundary events in the Algarve Basin.
Abstract: For historical and geological reasons the dinosaurian fossil record from central Europe is little known. Here we describe and interpret a portion of a left humerus from the Upper Maastrichtian of Vratsa district in north-western Bulgaria. This bone is the first known record of a dinosaur from Bulgaria; it is certainly a theropod, probably an ornithomimosaur. We discuss the fossil record of other similar fossils of theropod dinosaurs, in particular other problematic remains from the Maastrichtian of Belgium. Rare Earth Element (REE) analysis combined with strontium (Sr) isotope data demonstrate that the Bulgarian dinosaur was initially fossilised in a terrestrial environment and then later re-worked into Late Maastrichtian marine sediments.
Abstract: New cranial and postcranial material from a spinosaurid theropod dinosaur from the Early Cretaceous (Barremian) of Portugal is here reported. This specimen was found in Praia das Aguncheiras, Cabo Espichel in Boca do Chapim Formation, corresponding to a lagunar sedimentary environment (Rey, 1972). The specimen was disarticulated, suggesting it had been transported.
This specimen can be ascribed to Spinosauridae aff. Baryonyx walkeri on the basis of: (1) the crenulated and wrinkled ornamentation of teeth and (2) sigmoidal dorsal margin of the dentary. The serrated teeth in mesial and distal margins may ascribe this specimen to Baryonychinae. Recently Baryonyx walkeri has been reported to Portugal from the same area (Buffetaut 2007), however the specimen was extremely fragmentary. Spinosaurid dinosaurs are only represented by Baryonyx in Europe, namely Spain, England and Portugal. The specimen here reported (ML1190) comprises a partial ramus of the mandible, isolated tooth, pedal ungual phalanx, two calcanea, pre-sacral and caudal vertebrae, fragmentary ischium, pubis, scapula, and rib fragments. Thus, is the most complete Spinosauridae discovered in the Iberian Peninsula.
Abstract: Sauropods are often considered to have very limited mobility and reduced limb flexibility, mainly due to their giant size and consequent weight. In the Upper Jurassic Lourinhã Formation, central-west Portugal, deep vertical natural casts of sauropod manus tracks are often preserved as the infills of the original tracks. These manus tracks are vertical-walled, with marks of the striations of the skin scales, showing that the movement of the sauropod manus impacting and exiting the mud was totally vertical with no horizontal component of the stride. Some tracks are up to 66 cm deep, which is equivalent to the height of whole sauropod manus. This means that sauropods could lift their anterior feet in a complete vertical manner. Such movement is only possible if there is mobility at elbow and shoulder articulations in a higher degree than previously thought for sauropods. Our vision of sauropod limbs as inflexible columns has to be updated to a more dynamic model for limbs and body.
Abstract: Here we describe a new species of the mosasaurine genus Prognathodon from the Maastrichtian of
Namibe, Angola, on the basis of five specimens which represent most of the cranial skeleton including the
diagnostic quadrate. Phylogenetic analysis shows this new taxon, P. kianda nov. sp., to be the sister taxon to all
other species of Prognathodon. It is unique amongst Prognathodon in possessing a high marginal tooth count and
relatively small pterygoid teeth. The tooth morphology in the new taxon is reminiscent of some species of the
genus Liodon, allowing association of Liodon-like dentition with otherwise Prognathodon-like crania, and thus
resolves the long-standing question of the phylogenetic affinities of Liodon.
Abstract: Portugal has been providing dinosaur remains since, at least, 1863. The 18th century tiles depicting the legend of Our Lady in Cabo Espichel are probably the oldest known dinosaur track illustration. To our knowledge, the first remains found in Portugal were theropod teeth collected near Porto das Barcas (Late Jurassic of Lourinhã) in June 20th, 1863 by the geologist Carlos Ribeiro (1813-1882).
The first dinosaur paper was written by Henri Sauvage (1842-1917) published in 1896. All remains collected since 19th century were gathered in a work signed by Albert de Lapparent (1905-1975) and Georges Zbyszewski (1909-1999 ) titled Les Dinosauriens du Portugal (1957) that was a significant milestone in the Portuguese dinosaur paleontology and gives the state-of-the-art by the time. Several dinosaurs are named, described, depicted and mapped in that monograph. The first track record is given by Jacinto Pedro Gomes (1844-1916) in 1916. Concerning the non-scientific literature referring to dinosaurs, in 1884 the newspaper Occidente reports the Bernissart findings in Belgium.
In the 1959 occurs the first visit to Portugal of Walter Kühne (1911-1991) from the Free University of Berlin. Further visits and work granted the access to the Guimarota Mine and other Late Jurassic deposits in the 1960âs, 70âs and 80âs with a high number of publications. In the 1980âs and early 1990âs starts a progressive era for dinosaur paleontology in Portugal with the works of Peter Galton, Miguel Telles Antunes, the Natural History Museum, the Museum of Lourinhã and the New University of Lisbon, Oliver Rauhut, and others.
Abstract: Recent field work in Angola has led to the discovery of new specimens of the Turonian mosasaur
Angolasaurus bocagei providing new details of the anatomy of this taxon and allowing reassessment
of its phylogenetic position. One of the new specimens was encased in a well-cemented sandstone and
preserved in a fashion similar to the type specimen, but is significantly less crushed than the type. A
second unprepared specimen includes an articulated skull and partial postcrania in a poorly-cemented
sandstone matrix, and promises to be the best representative of this taxon known to date. The type
specimen and one of the new specimens were CT scanned to study previously unavailable details of
the internal surfaces and the skull and braincase. Additionally a series of braincase CT scans of
Turonian through Campanian plioplatecarpine mosasaurs was performed for comparison and
assessment of characters such as basalar artery path. Phylogenetic analysis supports a sister-taxon
relationship to the clade Platecarpus + Plioplatecarpus but indicates that the ascription of
Angolasaurus bocagei to the genus Platecarpus is unjustified.
Abstract: Although occurrences of marine reptiles have been previously reported from Angola, with the
exception of two Turonian taxa, these reports were based largely on isolated teeth. Fieldwork in 2005
and 2006 yielded well-preserved remains of marine reptiles including plesiosaurs, turtles, and
mosasaurs. The mosasaurs discussed here were recovered from two field areas: Turonian sediments at
Iembe along the north coast and Maastrichtian sediments at Bentiaba on the south coast. The
Turonian section near Iembe produced at least two new specimens of Angolasaurus bocagei and one
fragmentary specimen of Tylosaurus iembeensis. One of the Angolasaurus specimens is represented
by a well preserved, complete and articulated skull and partial postcrania, including portions of the
forelimbs and pectoral girdle. The preservation of material from the Bentiaba locality is remarkable
due to the grain support of the entombing sandstone, which preserves fine anatomical details with
little apparent crushing, and in the number of articulated, semi-articulated, and associated skeletons.
Identifications from the field and preliminary preparation show the Bentiaba mosasaur fauna is
represented by at least five genera including Mosasaurus, Prognathodon, Globidens, Plioplatecarpus
and Halisaurus. Collectively, these new specimens greatly expand our knowledge of the anatomy and
systematics of Angolan mosasaurs.
Abstract: Sedimentological features of the Paimogo site, 6 km NNW of Lourinhã, western central Portugal are presented. More than one hundred theropod dinosaur eggs (some containing embryo bones) ascribed to Lourinhanosaurus antunesi Mateus 1998, three crocodilian eggs and some other fossils were found at the 32 m2 excavated area of the egg-bearing horizon (Mateus et al., 1998). The stratigraphic position of the site is the Praia Azul member (Lourinhã Formation), roughly corresponding to the Kimmeridgian-Tithonian boundary or, more likely lowermost Tithonian. The maximum flooding surface of the basinal transgressive event where the horizon is located corresponds to the base of the H depositional sequence defined by Pena dos Reis et al. (2000) and probably correlates to the base of sequence Ti1 identified within western European basins (Jacquin et al., 1998), dated as 150 Ma.
Possibly during the normal river discharge, the theropods congregated in nesting colonies at the backswamp of an extensive flood plain with small meandering channels and
freshwater ponds. There are no evidences that the nest was dug or the eggs buried. The eggs have probably been laid on a flat, shaded, muddy area near the bank of a large pond. It is probable that the eggs have not been actively incubated. The larger number of eggs suggest that they were laid near simultaneously by, at least, six females. The fossil record shows that crocodilians, mammals, gastropods and fish were also present.
A flood event occurred when theropod embryos had attained a late stade of ontogenetic development, probably just before hatching. The overflow from a nearby channel flooded
the plain, including the area where the eggs had been laid. The sheet flood flowing over the nest resulted into the scattering and breaking up of some dinosaur eggs. Eggshell and embryos skeletal parts fragments were displaced to an adjacent area where, due to hydrodynamic decline, the flow submerged other clutches and moderately dragged their eggs. The flooding caused the drowning of the embryos and covered the eggs with fine-grained sediment, hiding them from predators and scavengers. Hydrodynamic interpretation of the arrangement of the theropod eggs and egg-fragments suggests that the flow came from the NW.
When the floodwaters receded, the fine-grained deposits became exposed to subaerial weathering. Although the sediment surface was often wet and small bodies of standing
water may still have existed, the sediments were oxidized and plant remains have consequently been destroyed. Some carbonate cementation and redenning resulted from pedogenesis under alternating dry and moist conditions, in a semiarid/ sub-tropical climate under seasonal changing, contrasting conditions. The thick, stratigraphically above and below the nesting horizon mudrocks indicate a long persistence of periodic flooding, alternating with pedogenesis. During the early stages of diagenesis, vertical pressure
crushed the eggs. Silt penetration into the inner part of each egg inhibited later flattening during the burial process.
