SOCIETY OF PALEONTOLOGY OCTOBER 2015 ABSTRACTS OF PAPERS 75th ANNUAL MEETING

Hyatt Regency Dallas Dallas, Texas, USA October 14 – 17, 2015

HOST COMMITTEE Stephen Cohen; Anthony R. Fiorillo; Louis Jacobs; Michael Polcyn; Amy Smith; Christopher Strganac; Ronald S. Tykoski; Diana Vineyard; Dale Winkler

EXECUTIVE COMMITTEE John Long, President; P. David Polly, Vice President; Catherine A. Forster, Past-President; Glenn Storrs, Secretary; Ted J. Vlamis, Treasurer; Elizabeth Hadly, Member-at-Large; Xiaoming Wang, Member-at-Large; Paul M. Barrett, Member-at-Large

SYMPOSIUM CONVENORS Larisa R. G. DeSantis; Anthony R. Fiorillo; Camille Grohé; Marc E. H. Jones; Joshua H. Miller; Christopher Noto; Emma Sherratt; Michael Spaulding; Z. Jack Tseng; Akinobu Watanabe; Lindsay Zanno

PROGRAM COMMITTEE David Evans, Co-Chair; Mary Silcox, Co-Chair; Heather Ahrens; Brian Beatty; Jonathan Bloch; Martin Brazeau; Chris Brochu; Richard Butler; Darin Croft; Ted Daeschler; David Fox; Anjali Goswami; Elizabeth Hadly; Pat Holroyd; Marc Jones; Christian Kammerer; Amber MacKenzie; Erin Maxwell; Josh Miller; Jessica Miller-Camp; Kevin Padian; Lauren Sallan; William Sanders; Michelle Stocker; Paul Upchurch; Aaron Wood

EDITORS Amber MacKenzie; Erin Maxwell; Jessica Miller-Camp

October 2015 PROGRAM AND ABSTRACTS 1 Grant Information dinosaur-bearing units in the world. Though exposed in Saskatchewan, outcropping is NSF grant #0847777 (EAR) to D.J. Varrichio sparse, widely distributed, and often difficult to access. Despite this, recently, several microfossil sites have been identified throughout southwestern Saskatchewan, Canada. Technical Session VI (Thursday, October 15, 2015, 9:00 AM) The Saskatchewan sites produce a rich vertebrate record, including chondrichthyans, osteichthyans, turtles, champsosaurs, crocodiles, squamates, amphibians, birds, MULTIDENTICULATE TEETH IN FISH HEMICALYPTERUS WEIRI , and dinosaurs. Integration of geological and paleontological information to (OSTEICHTHYES: ACTINOPTERYGII): EVIDENCE FOR A SPECIALIZED place these sites into a geological context, as well as a meaningful microfossil database, FEEDING NICHE IN THE MESOZOIC LV RQJRLQJ 'XH WR WKH SURYLQFHV¶ SUR[LPLW\ WR WKH WUDQVJUHVVLYH %HDUSDZ 6HD GIBSON, Sarah Z., University of Kansas, Lawrence, KS, United States of America, paleocoastline, these sites offer a unique opportunity to test paleoecological hypothesis 66045 regarding community response to sea level rise and inundation across the coastal and Fishes are one of the largest extant vertebrate groups, and occupy multiple alluvial plain of Western Canada. ecological niches. Many living fishes have evolved specialized multidenticulate teeth that are often associated with a herbivorous or omnivorous lifestyle, and fishes with this Technical Session IV (Wednesday, October 14, 2015, 2:15 PM) specialized dentition occur in both marine (e.g., surgeonfishes, rabbitfishes) and freshwater (e.g., haplochromine cichlids, characiforms) systems. These fishes often NEW PARTIAL SKELETON, BODY SIZE, AND BRAIN SIZE IN THE LATE exploit a benthic feeding behavior, using their multicuspid teeth to scrape algae or WHALE ZYGORHIZA KOCHII, AND A COMPARISON OF attached invertebrates from a hard substrate. The fossil record for this unique tooth ENCEPHALIZATION RESIDUALS IN (MAMMALIA, morphology is limited, and fishes displaying multidenticulate dentition only extend into ) the Eocene. I report evidence of the oldest example of specialized multicuspid dentition GINGERICH, Philip D., University of Michigan, Ann Arbor, MI, United States of in a ray-finned fish, Hemicalypterus weiri, from the Upper Triassic Chinle Formation America, 48109-1079 Zygorhiza kochii (~210±205 Ma) of southeastern Utah. Hemicalypterus possessed a deep, disc-shaped A new partial skeleton of the late Eocene archaeocete is described, body, ganoid scales covering only the anterior half of the body, and a scaleless posterior based on a Field Museum specimen from the Pachuta Marl member of the Yazoo Z. kochii flank, which likely aided in flexibility. Hemicalypterus also possessed several Formation near Melvin, Alabama. The body weight of is estimated to have been Zygorhiza multidenticulate teeth on the premaxilla and dentary; each tooth has a rounded base, a about 1077 kg, based on vertebral size. The new skeleton includes a cranium flattened, scoop-like crown, and terminates with four individual cusps. The morphology with a well preserved braincase, which has yielded one of the best endocranial casts of these specialized teeth converges with many living teleost fishes, and these scoop-like known for an archaeocete. The endocast has the large dorsal and rostral retia mirabilia edges likely allowed Hemicalypterus to effectively scrape algae off of a rock substrate. characteristic of basilosaurids. The dorsolateral surface of the cerebrum, where exposed, This discovery fundamentally alters perceptions of the ecological roles of fishes during is smoothly curved, with no suggestion of the cortical folding characteristic of modern the Mesozoic, which were previously hypothesized to be limited to generalist or cetacean brains. durophagous feeding niches. This finding indicates that specialized dentition associated Encephalization is necessarily quantified relative to a reference sample, and with herbivory is not restricted to teleosts and that fishes likely exploited a herbivorous or terrestrial mammals provide a logical baseline. The encephalization residual for living omnivorous scraping ecological niche long before previously thought. terrestrial mammals as a class (ERTC) is the difference between observed log2 brain weight (Ei in g) and expected log2 brain weight (Ee in g), where the latter is estimated Poster Session I (Wednesday, October 14, 2015, 4:15 - 6:15) from log2 body weight (Pi in g) as Ee   Â 3i í 4.004. A log base-2 ER scale is intuitive as it involves halvings and doublings on a uniform arithmetic scale, and it is NEW SIVALADAPID PRIMATE FROM SUNETAR, A LOWER SIWALIK appropriate for the observed range of encephalization differences. Encephalization LOCALITY NEAR THE TOWN OF RAMNAGAR (JAMMU AND KASHMIR, quotients (EQ) are unsuitable for comparison because they are proportions on a non- INDIA) uniform scale. GILBERT, Christopher C., Hunter College, CUNY, New York, NY, United States of Endocranial volume of the skull of Zygorhiza kochii is 1189 cm3, which, when retia America, 10065; SINGH, Ningthoujam P., Panjab University, Chandigarh, India; mirabilia are subtracted, corresponds to a brain weight of about 960 g. This yields an PATEL, Biren A., University of Southern California, Los Angeles, CA, United States of encephalization residual, ERTC, for Z. kochii RIíDQGDQHQFHSKDOL]DWLRQTXRWLHQW America; FLEAGLE, John G., Stony Brook University, Stony Brook, NY, United States EQTC = 2 ^ ERTC = 0.53. Middle Eocene archaeocetes have ERTC YDOXHVFORVHWRí WZR of America; PATNAIK, Rajeev, Panjab University, Chandigarh, India halvings compared to expectation), while late Eocene archaeocetes have ERTC values Lower Siwalik fossil localities near the town of Ramnagar, India are well known to FORVH WR í Rne halving compared to expectation). ERTC is not known for fossil vertebrate paleontologists. Over the past century, numerous specimens collected near mysticetes, but living mysticetes have ERTC YDOXHV DYHUDJLQJ DERXW í 2OLJRFHQH± Ramnagar have proven important to understanding the evolution and biogeography of Recent odontocetes appear to have ERTC values averaging about +1 (one doubling many mammalian groups. Primates from Ramnagar, though rare, include a number of compared to expectation) through their temporal range. Definitive interpretation of hominoid ape fossils attributable to Sivapithecus as well as a single published mandibular patterns of encephalization will require better documentation for all three groups, fragment preserving the p4±m1 of the Miocene adapoid Sivaladapis palaeindicus. Since Archaeoceti, Mysticeti, and Odontoceti. 2010, we have renewed fossil prospecting in the Lower Siwalik deposits near Ramnagar in an attempt to better understand the evolution, biogeographic timing, and paleoclimatic context of mammalian radiations in Asia, with a particular focus on primates. To date, Poster Session III (Friday, October 16, 2015, 4:15 - 6:15) our explorations have resulted in the identification of new fossil localities in the ON THE NATURE OF ULTRASCULPTURE IN THE DERMAL SKELETON OF Ramnagar area, including the site of Sunetar. In October 2014, a partial mandible of a PSAMMOSTEIDS (AGNATHA: PTERASPIDIFORMES) sivaladapid was recovered at Sunetar, preserving the mandibular corpus with worn m1± GLINSKIY, Vadim, Saint Petersburg State University, Saint Petersburg, Russia; m3 dentition. Although sivaladapids are known by numerous specimens of two genera PINAKHINA, Darya, Saint Petersburg State University, Saint Petersburg, Russia (Sivaladapis and Indraloris) at Lower Siwalik sites on the Potwar Plateau and at the The ultrasculpture present on the superficial layer of the dentin tubercles of Middle Siwalik locality of Haritalyangar, this new specimen is just the second known psammosteids is represented by cell-sized polygons, separated by walls or grooves. This sivaladapid primate from the Ramnagar region. We compared measurements of the type of ultrasculpture can be formed by epithelial cells (10-30 μm length) or ameloblasts Sunetar specimen with those taken from Sivaladapis and Indraloris specimens in (approximately 3-6 μm in length). The finding of small-sized ultrasculpture in museum collections as well as the literature. Our results suggest that Sivaladapis can be psammosteids have led some authors to assumption that its origin is connected with reliably distinguished from Indraloris by its significantly narrower molars and enameloid tissue. Research has been carried out in order to verify information about the significantly more compressed molar trigonids. For m1±m3, the Sunetar specimen either absence of enameloid in psammosteids. The tubercles of three species of psammosteids falls close to or within the range of Sivaladapis for these two molar features and outside with different stratigraphic ranges (Ganosteus stellatus, Psammosteus livonicus, of the Indraloris range. Because the Sunetar specimen is most similar in overall molar Psammosteus falcatus) were fixed in epoxy resin and ground down horizontally. They shape to Sivaladapis, and yet 20% smaller than known Sivaladapis taxa, we suggest that were subsequently etched with 2N HCl for 2-15 seconds. The prepared tissues were it may represent a new species similar in absolute size to I. kamlialensis from the Potwar examined under scanning electron microscope (SEM). It appeared that the superficial Plateau. The age of Sunetar and the Ramnagar region, in general, can be bracketed by the OD\HULQKRUL]RQWDOVHFWLRQVRIWKHWKUHHVSHFLHVLVFRPSRVHGRIRUWKRGHQWLQDQGGRHVQ¶W suid Conohyus and the rodents Antemus chinjiensis and Kanysamys cf. potwarensis to an differ from the inner layers. The study of ultrasculpture in psammosteids belonging to approximate age of 14 Ma±12.7 Ma. However, future collection efforts and four different families (Pycnosteidae, Psammolepididae, Psammosteidae, paleomagnetic studies are still necessary to confidently and more precisely resolve the Guerichosteidae) under the SEM has shown that its average size is 8-11 μm. age of the Ramnagar deposits. The distribution of ultrasculpture is generally limited to the lower half of the Grant Information tubercles with vertically oriented crowns. In the case of tubercles with low crowns, or This study was generously supported by the PSC-CUNY faculty research award program, slanted tubercles, the ultrasculpture covers almost the whole surface. On those tubercles Hunter College, AAPA Professional Development Program, and Wenner-Gren which underwent intravital abrasion and on secondery tubercles as well as "blisters", the Foundation. ultrasculpture is preserved in uninvolved bottom regions. Histological research and measurements of ultrasculptural polygons confirm the Poster Session II (Thursday, October 15, 2015, 4:15 - 6:15) absence of enameloid in psemmosteid tubercles. One of the functions of ultrasculpture was attachment of epidermis to the surface of the dermal skeleton. It has been discovered NEW MICROVERTEBRATE MATERIAL FROM THE BELLY RIVER GROUP, that the upper limit of distribution of ultrasculptural imprints corresponds to the height of DINOSAUR PARK FORMATION (CAMPANIAN) OF SOUTHWESTERN distribution of microtubercles on the radial ribs and crenulations. Therefore, the function SASKATCHEWAN, CANADA of microtubercles could be reinforcement of fixation of epidermis. GILBERT, Meagan M., University of Saskatchewan, Saskatoon, SK, Canada, S7N 5E2; Grant Information BUATOIS, Luis, University of Saskatchewan, Saskatoon, SK, Canada; RENAUT, Robin, RFBR, research project No. 14-04-01507 a, St. Petersburg State University research grant University of Saskatchewan, Saskatoon, SK, Canada 0.38.292.2015 The Belly River Group comprises an eastward-thinning paralic to non-marine Campanian clastic succession in the Western Canadian Sedimentary Basin. Three formations are formally recognized in the western Canadian Plains. In ascending order, these are the Foremost, Oldman, and Dinosaur Park formations. In Alberta, the Group is well known for its rich and diverse vertebrate fauna, and is one of the most productive

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