hosted by
publicationslist.org
    

Brian Lee Beatty


bbeatty@nyit.edu

Journal articles

2010
2009
B L Beatty, L D Martin (2009)  The earliest North American record of the Antilocapridae (Artiodactyla, Mammalia)   PaleoBios 29: 1. 29-35  
Abstract: The Family Antilocapridae is considered to have first appeared in the Early Hemingfordian of western North America. Here we report a mandible of a merycodontine antilocaprid from the Late Arikareean Harrison Formation of eastern Wyoming. The mandible has three lower molars preserved and mandibular ramus features that allow it to be differentiated from other contemporaneous selenodont artiodactyl families, yet the lack of detailed understanding of intraspecific variation in Paracosoryx and Merycodus warrant caution in assigning this to a genus. This new material predates the previous first appearance of antilocaprids by approximately 3–4 million years and suggests that antilocaprid immigration from Eurasian ruminant stock occurred earlier than previously assumed and that caution should be exercised when using first appearances in broader analyses.
Notes:
B L Beatty, B M Rothschild (2009)  Paleopathologies are features of an organism and its interaction with the environment and should not be treated like organisms unto themselves   Historical Biology 21: 3-4. 229-233 Dec  
Abstract: Though the history of disease has an evolutionary history in itself, this history of pathologies, which are physical manifestations of immune responses to disease processes, has a history that is intimately linked to the history of the host organisms themselves. But many of these physical manifestations of an organism’s response to disease are related to aspects of the immune system that are rooted so deeply in the phylogeny of vertebrates, or at least amniotes, that one must exercise caution when interpreting a pathology as novel. Here, we argue that the interpretation of paleopathologies must be founded on the basis of disease manifestations which relate to phylogeny, but recognise that much of this relationship is so deeply rooted that novel paleopathologies would be rare. The former presents an interesting speculation, but does not allow for placement of findings within an ecological and chronological context. Likewise, the assignment of specimens as paleopathological holotypes defeats this purpose in attempting to narrowly define the physical manifestation of the immune response to disease, doing nothing more than a photographic library of paleopathologies could do, but not conveying the true nature of paleopathologies and could lead to artificial classification schemes that would cause more confusion than clarity.
Notes:
B L Beatty, A C Dooley (2009)  Injuries in a Mysticete Skeleton from the Miocene of Virginia, With a discussion of Buoyancy and the Primitive Feeding Mode in the Chaeomysticeti   Jeffersoniana 20: 1-28  
Abstract: A mostly complete skeleton of a mysticete from the Carmel Church Quarry displays some injuries, including a fractured and partially-healed left mandible, previously not reported in any fossil mysticete. The mostly healed nature of this non-union impaction fracture indicates that the animal died a significant amount of time after the injury. Additional injuries of the postglenoid process and left premaxilla, as well as the nature of the impaction fracture in the mandible suggest that the cause of this was some impact from the left anterior aspect. Possible scenarios for how this injury could have happened include intraspecific aggression and, more likely, impact with the seafloor during benthic feeding. The ribs of this individual are heavily osteosclerotic from dorsal to ventral ends, which would suggest that this taxon was a benthic feeder. In comparison with a sample of ribs from fossil mysticetes, it appears that Diorocetus may have been one of the last mysticetes with rib osteosclerosis, a feature possibly primitive to Mysticeti. Although this remains speculative, the presence of osteosclerotic ribs in primitive mysticetes suggests that the feeding mode employed by the earliest Chaeomysticeti was one of benthic feeding.
Notes:
B L Beatty, A B Heckert (2009)  A large archosauriform tooth with multiple supernumerary carinae from the Upper Triassic of New Mexico (USA), with comments on carina development and anomalies in the Archosauria   Historical Biology 21: 1&2. 57-65  
Abstract: Here we report a tooth of a large archosauriform from the Upper Triassic of New Mexico, USA that displays developmental anomalies of carina formation. This tooth has two supernumerary carinae, both on the lingual side of the tooth. Previously, carina anomalies of this sort were primarily known from theropod dinosaurs, but always from the labial surface. Integrating this specimen into a reassessment of the published accounts of carina anomalies in other fossil diapsids reveals that supernumerary carinae are more widespread throughout Archosauriformes than previously reported. Our interpretation of this developmental anomaly highlights the present lack of understanding of tooth development in archosaurs, particularly carina formation, and suggests that crown morphology development in archosauriforms may be constrained differently than it is in mammals. This developmental constraint may explain the differences observed between the complexity found in mammal and archosauriform cusp morphology.
Notes:
B L Beatty (2009)  New Material Cornwallius sookensis (Mammalia: Desmostylia) from the Yaquina Formation of Oregon   Journal of Vertebrate Paleontology 29: 3. 894-909 September  
Abstract: Although many desmostylian genera, including Behemotops katsuiei, Desmostylus hesperus, Paleoparadoxia tabatai, P. weltoni, P. repennngi, and Ashoroa laticosta are known from skulls and postcrania, Cornwallius sookensis has previously been known only from isolated teeth. New material from the Emlong Collection of the Smithsonian Institution is described here. ThNew MaterCornwallius Sookensis skulls, four partial mandibles, four isolated teeth, an innominate and a tibia from the Yaquina Formation of coastal Oregon (Zemorrian, Oligocene). The diagnosis of this taxon is emended to include the development of a postorbital process of the jugal, a dorsal midsagittal keel of the rostrum, paraglossal crests of the maxillary diastema, and a sagittal crest. Dental characteristics, including identification of canines and cusp homologies, are defined. Though the skulls and mandibles described are nearly complete, some premolars are missing and alveoli are damaged, making interpretation difficult. The adult dental formula is tentatively interpreted as 2.1.2?.3/ 1.1.1?.3, although the deciduous dentition includes two pairs of lower incisors. Mandibular characteristics include a posteriorly sloped anterior edge of the coronoid process. Phylogenetic analysis incorporating this new information resulted in one most parsimonious tree for the Order Desmostylia. The families Paleoparadoxiidae (comprising three Paleoparadoxia species) and Desmostylidae (comprised of Ashoroa, Cornwallius, Desmostylus, and Vanderhoofius) are found to be distinct clades. The clade including both species of Behemotops (Behemotopsidae) is found to be the sister group to the clade comprising Paleoparadoxiidae and Desmostylidae.
Notes:
2008
B L Beatty, B M Rothschild (2008)  Decompression syndrome and the evolution of deep diving physiology in the Cetacea   Naturwissenschaften 95: 9. 793-801 September  
Abstract: Whales repetitively dive deep to feed and should be susceptible to decompression syndrome, though they are not known to suffer the associated pathologies. Avascular osteonecrosis has been recognized as an indicator of diving habits of extinct marine amniotes. Vertebrae of 331 individual modern and 996 fossil whales were subjected to macroscopic and radiographic examination. Avascular osteonecrosis was found in the Oligocene basal odontocetes (Xenorophoidea) and in geologically younger mysticetes, such as Aglaocetus [a sister taxon to Balaenopteridae + (Balaenidae + Eschrichtiidae) clade]. These are considered as early “experiments” in repetitive deep diving, indicating that they independently converged on their similar specialized diving physiologies.
Notes:
2007
D P Domning, B L Beatty (2007)  Use of tusks in feeding by dugongid sirenians: Observations and tests of hypotheses   The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology 290: 6. 523-538  
Abstract: Most living and fossil sea cows of the subfamily Dugonginae (Dugongidae, Sirenia, Mammalia) are characterized by large upper incisor tusks, which are thought to play an important role (at least primitively) in feeding on seagrass rhizomes. Testing this hypothesis is difficult, because the only extant tusked sirenian (Dugong dugon) is morphologically and perhaps behaviorally aberrant. The tests attempted here involve examination of stomach contents of wild Recent dugongs, experiments using plastic replicas of diverse tusks to harvest seagrasses, gross anatomical observations on tusks and skulls, measurements of tusk tip geometry, and observations of microwear on tusks. We conclude that (a) male D. dugon (with erupted tusks) do not consume more rhizomes than females (without erupted tusks); (b) the tusks do not play a significant role in feeding in the modern dugong; (c) larger, more bladelike tusks are more effective at harvesting rhizomes, but the effect of shape was not experimentally separated from the effect of exposed tusk length; (d) some fossil dugongines show apparent cranial adaptations for downward and backward cutting motions of their large, bladelike tusks; (e) geometry of wear surfaces is consistent with use of at least the more bladelike tusks as cutting instruments; (f) preliminary observations of microwear in D. dugon do not indicate more than occasional use of the tusks in purposeful harvesting of rhizomes, and then only opportunistically by large adult males. The hypothesis of such tusk use by extinct dugongines (in contrast to the living species) is so far corroborated, but available data and tests do not suffice to establish this conclusively.
Notes:
2006
B L Beatty (2006)  Rediscovered specimens of Cornwallius (Mammalia, Desmostylia) from Vancouver Island, British Columbia, Canada.   PalArch's Journal of Vertebrate Palaeontology 2006: 1. 1-6  
Abstract: Specimens initially collected but not reported from the original type locality of Cornwallius sookensis (Mammalia, Desmostylia) have been found at the National Museum of Natural History in Washington, DC. Two femora and a partial skull were collected from the same locality as the holotype that was deposited by Ira Cornwall in the Royal British Columbia Provincial Museum in the 1920s. Though the partial skull is missing from the collection, the femora remain. They are small and lack epiphyses, possibly from breakage or immaturity. Muscle scars suggest that adductors, extensors and lateral rotators were strongly developed, indicating that their posture was of the normal mammalian upright nature. The sectioned end of USNM 11076 permits inspection of characteristics of the medullary canal and cortical.
Notes:
2003
S D Webb, B L Beatty, G Poinar (2003)  New Evidence of Miocene Protoceratidae Including a New Species from Chiapas, Mexico   Bulletin of the American Museum of Natural History 279: 348-367  
Abstract: We describe Paratoceras tedfordi, a new species of Protoceratidae from early Miocene amber-bearing sands near Simojovel, Chiapas, southern Mexico. The holotypic cranium weakly expresses maxillary plates, supraorbital rugosities, and a median occipital projection as in the type of Paratoceras wardi, and is interpreted as a female. Its short facial region, elongate premolars, and brachydont molars place it among the Protoceratinae, not Synthetoceratinae. We also describe new cranial and the first postcranial material of Prosynthetoceras texanus from Alum Bluff and Thomas Farm sites in Florida. Incorporating data from these new specimens, we consider highlights of protoceratid adaptive morphology including their elaborate male ossicones, tapirlike proboscis, brachydont to mesodont dentition, and limb features and proportions. We suggest that progressive protoceratids may be seen as ecological analogues of the Bushbuck of South Africa, a forest-adapted browser. Each of the three groups of horned Protoceratidae speciated allopatrically along latitudinal lines, with the northern branch becoming extinct earlier than its southern sister. Their greater proclivity toward survival in tropical latitudes explains the importance of Protoceratidae in the Gulf Coastal Plain during the Miocene, and evident higher abundance of Paratoceras in Central America.
Notes:

Book chapters

2010
B Beatty, A Dooley (2010)  More than Just Old Bones: The Fossil Record Informs us About Homology, and Convergences of Anatomy, Physiology and Behavior in the Cetacea otherwise Unknown from Modern Animals   In: Whales and Dolphins: Behavior, Biology and Distribution Edited by:Craig Murray. 129-140 Nova Science Publishers isbn:978-1-61668-693-2  
Abstract: The biology of cetaceans is one of the most compelling because of the extreme adaptations whales and dolphins have had to evolve to manage a life in water. The fossil record of cetaceans is rich, and though much attention has been given to the origins of whales from terrestrial artiodactyls, it is important to realize that the biology, physiology, and behavior of modern cetaceans has not remained unchanged since this initial transition to being aquatic. Here I review some examples of how the fossil record of cetaceans informs us of how the evolution of anatomy, physiology and behavior has diverged and converged between and within the Odontoceti and Mysticeti in ways that would not be known if one were only to study their living representatives. Studies of paleopathologies associated with decompression syndrome inform us that odontocetes and mysticetes independently evolved specializations for repetitive deep diving. Cross sectional anatomy of ribs from modern and fossil mysticetes indicates that mysticetes started out with hyperdense skeleton and were probably benthic feeding, only to converge on the osteoporosis-like state found among most modern mysticetes and odontocetes. In the end, these studies of fossil cetaceans highlight the fact that many of our assumptions about homologies of anatomy, physiology, and behavior in modern cetaceans may be misled by only studying modern cetaceans, and that interpretations of modern animal biological data that rely on these sorts of assumptions should be reconsidered.
Notes: this chapter is OPEN ACCESS

book reviews

2009

Encyclopedia entry

2010
B Beatty (2010)  What is a placental?   online [Encyclopedia entry]  
Abstract: Most mammal species living today are placental mammals. This includes such commonly known groups as bats, dogs, cows, elephants, dolphins, and manatees. Mammal diversity is not limited to these groups, however, and the fossil record indicates that although the diversity of modern mammals is dominated by placental mammals, more than half of the history of mammals is dominated by other groups, starting with early mammal diversification in the Triassic. Still, since the end of the Cretaceous period and the extinction of non-avian dinosaurs (all dinosaurs except for their bird descendents) 65 million years ago, placental mammals have undergone an explosive diversification. Modern mammals fall into three groups that can be defined by their reproductive systems: Monotremata (monotremes such as the echidna and platypus), Metatheria (marsupials), and Eutheria (placental mammals). Monotremes are very different from other modern mammals in that they lay eggs. This is considered the primitive condition for early mammals after their divergence from reptiles. Unlike monotremes, eutherians and marsupials both give birth to live young and both have a placenta, although the placenta of marsupials is much more short-lived than that of placental mammals and therefore plays a lesser role in providing nourishment to young. Gestation in marsupials is short, resulting in live birth of altricial young; that is, young are born at a very early stage in their development. Eutherians give birth to comparatively precocial young; that is, young are born at a later stage in their development. In eutherians the young are nurtured inside the body of the mother by the placenta, which allows nutrients to pass from the blood of the mother almost directly into the blood of the young, an efficient way of ensuring early development in a secure environment. Although the term Placentalia is often used interchangeably with Eutheria, Placentalia is best used as a term for the modern placental mammals only, whereas Eutheria is strictly defined as the entire clade, including extinct forms. A clade is a group of species that includes an ancestral species and all its descendants—essentially what one might consider an entire branch and all of its smaller twigs on a tree of life. As will become evident in the following discussion, this is perhaps a more accurate means of reflecting the known diversity and ecology of placental mammals, both present and past, as well as avoiding confusion arising from the presence of a placenta in marsupials. (This Introduction is followed by 4 more pages on the diversity, fossil record, and ecology of placental mammals, including a review of the origins of modern placental orders from Cretaceous groups, current to what was known as of late 2009.)
Notes:
Powered by PublicationsList.org.