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NEW EARLY MIOCENE CAMELIDS (ARTIODACTYLA, FLORIDATRAGULINAE) FROM PANAMA AND THE RELATIONSHIP OF FLORIDATRAGULINES TO CAMELINAE

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Differences include the form of the internal tuberosity and capital incisura. To indicate
size, the humerus is about 84% as long as that of the late Oligocene Kairuku grebneffi for
which standing height was about 1.28 m.
The locality, in the Kyeburn region of Central Otago, is close to the southwest extent
of the Cretaceous-Cenozoic Canterbury Basin. Matrix from the penguin is a gypsiferous,
pyritic, decalcified glauconitic sandstone, from a marine shelf setting below wave base.
Formational name is uncertain because the local lithostratigraphy needs revision. The
matrix produced no foraminifera, but a nearby fossiliferous horizon produced
foraminifera consistent with local Kaiatan to Runangan stages, late Bartonian to
Priabonian (late Eocene). The association of bones from one individual suggests a quiet
setting, with minimal postmortem disturbance.
Grant Informati on
Benson Fund
Poster Session I (Wednesday, October 14, 2015, 4:15 - 6:15)
RARE DIRECT EVIDENCE OF ANGIOSPERM CONSUMPTION BY
DINOSAURS BASED ON COPROLITES FROM THE KAIPAROWITS
FORMATION OF UTAH
RIDGWELL, Nicole M., University of Colorado Boulder, Boulder, CO, United States of
America, 80301; CHIN, Karen, University of Colorado Boulder, Boulder, CO, United
States of America; UPCHURCH, Garland, Texas State University, San Marcos, TX,
United States of America; SERTICH, Joseph, Denver Museum of Nature & Science,
Denver, CO, United States of America
Although the ecological relationships between dinosaurs and angiosperms have long
been debated, very little direct evidence of angiosperm consumption has been found to
date. We report the discovery of two coprolites recovered from the Campanian
Kaiparowits For mation of southern Utah that contain fra gments of angiosperm wood.
One of the angiosperm coprolites was discovered as a group of associated float
fragments, the other was found in situ and removed intact. Both coprolites were found
near other herbivore coprolites that contain conifer but no angiosperm wood. Specimen
inclusions and ground mass were characterized by visual examination of exposed
surfaces and thin sections. Several lines of evidence support the conclus ion that these
specimens are coprolites including: (1) specimen ground mass is composed of
disaggregated plant cells in a calcareous matrix, which is distinctly different from the
clastic lithology of the host sediment; (2) inclusions include mm-scale fragments of plant
tissue and isolated angiosperm vessels; and (3) extensive bioturbation is present,
including many back-filled burrows. These indicators suggest feeding-induced
comminution and post-depositional reworking in a manner characteristic of
coprophagous insects.
The volume of the fragmented coprolite was at least 0.88 L, and the in situ coprolite
appears to be comparable in size. Other than ornithischian dinosaurs, no other large- or
medium-bodied plant eating animals have been found in the Kaiparowits Formation
assemblage to date that would have been capable of producing these coprolites, and only
ornithischians had dentition capable of the observed fine degree of comminution.
The coprolites contain inclusions indicating a diet that was not wholly herbivorous.
Fragments of mo llusk shell and one lizard dentary are embedded in interior surfaces of
the coprolites and therefore were most likely not introduced after deposition.
Angiosperms first appeared during the Early Cretaceous and diversified rapidly
throughout the Late Cretaceous. This time period also had great dinosaur diversity,
especially the Late Cretaceous Laramidian ecosystem represented by the Kaiparowits
Formation. The coprolites presented here reveal trophic interactions between
angiosperms and dinosaurs in the Kaiparowits. Moreover, their co-occurrence with
conifer-bearing coprolites may reflect ecological niche partitioning.
Poster Session II (Thursday, October 15, 2015, 4:15 - 6:15)
NEW EARLY MIOCENE CAMELIDS (ARTIODACTYLA,
FLORIDATRAGULINAE) FROM PANAMA AND THE RELATIONSHIP OF
FLORIDATRAGULINES TO CAMELINAE
RINCON, Aldo F., University of Florida, Gainesville, FL, United States of America,
32611; BLOCH, Jonathan I., University of Florida, Gainesville, FL, United States of
America
Floridatraguline camels are a tropical-subtropical North American clade with an
elongate rostrum and a shallow, narrow symphysial area. ? Poebrotherium franki from
the late Eocene of Texas is recognized as the oldest floridatraguline based on its
moderately elongate rostrum and laterally positioned upper incisors. Otherwise,
floridatragulines are restricted to the early Miocene, with Floridatragulus
dolichanthereus (~18.5 Ma; Hemingfordian) from Florida the best known. Primitive
camelid characteristics of F. dolichanthereus include brachydont dentition, posteriorly
open orbits, square upper molars, ectostylids on lowe r molars , and a divided /m3
hypoconulid, providing evidence that floridatragulines might represent a distinct group
only distantly related to the Arikareean 'higher camelids' with distinctive metastylids on
the lower mo lars (e.g., Gentilicamelus and Oxydactylus). Phylogenetic analysis based on
dental characters allies the Hemingfordian species of Floridatragulus from the Gulf
Coast with late Arikareean-Hemingfordian species of Aguascalientia from tropic al
Central America. Both genera may have subtropical origins linked to early Arikareean
higher camelids from the Gulf Coast. A new partial skull of Aguascalientia from Panama
(~21 Ma) not only has the distinctive floridatraguline morphologies listed above, but it
also has unique characteristics that are absent in F. dolichanthereus but shared with late
Arikareean higher camelids (e.g., nearly complete postorbital bar, double rooted P1/,
shallow maxillary fossa) suggesting the possibility that Floridatragulinae might be
paraphyletic with respect to Camelinae. Additional evidence suggesting a paraphyletic
Floridatragulinae comes from the first known partial dentitions of Floridatragulus from
Panama (~19 Ma) that are referable to F. nanus, otherwise only known from the early
Hemingfordian of the Gulf Coast. In contrast to the single-rooted /p1 of Aguascalientia
and F. dolichanthereus, F. nanus fro m Panama has a double-rooted /p1, further
suggesting that the skull elongation in both genera might be a result of convergence.
Panamanian floridatragulines also share cranial characteristics with even more derived
camelines (e.g., moderately elongate rostrum in Aguascalientia and proximal co-
ossification of the metapodials in F. nanus) found in the later Barstovian suggesting that
this radiation might be critical for understanding the evolution of crown Camelidae.
Grant Informati on
U.S. NSF Partnerships in International Research and Education grant 0966884 (OISE,
EAR, DRL), EAR 0824299, EAR 0418042
Poster Session IV (Saturday, October 17, 2015, 4:15 - 6:15)
RIO YUCA FORMATION: A NEW EARLY MIOCENE VERTEBRATE
ASSEMBLAGE FROM VENEZUELA
RINCÓN, Ascanio D., Instituto Venezolano de Investigaciones Cientificas (IVIC),
Caracas, Venezuela; MCDONALD, H. G., Museum Management Program, National
Park Service, Fort Collins, CO, United States of America; SOLÓRZANO, Andrés D.,
Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas, Venezuela; NÚÑEZ
FLORES, Mónica, Instituto Venezolano de Investigac iones C ientíficas (IVIC), Caracas,
Venezuela; MACSOTAY, Oliver, Urb. El Trigal Norte, Valencia, Venezuela
Early Miocene localities with vertebrate remains in northern South America are
scarce. This interval of time is crucial for our understanding about the general
assumptions of different biogeographic scenarios for this part of South America, such as
the changing course of the Paleo-Orinoco River. Recent geological explorations of the
mollassic beds of the Rio Yuca Formation (Portuguesa State, Venezuela) resulted in the
recognition of a new vertebrate assemblage. Previously, the only known fossil mammal
from this formation is the enig matic slot h, Pseudoprepotherium venezuelanum. The new
faunal assemblage includes mamma ls, c f. Nesodon (based on an isolated broken upper
premolar with the primary lingual enamel fold completely isolated, the presence of a
broad anterior enamel band, apparently an enamel band on the posterior cingulum,
straight ectoloph, oblique protoloph, and a transverse metaloph), an indeterminate
member of the Dasypodidae (based on a small osteoderm with a central figure enclosed
posteriorly); freshwater fishes, Phractocephalus sp. (based on a coarsely ornamented
fragment of skull with reticulating ridges and surrounding pits), an indeterminate
Pimelodidae (based on a partial skull which is unfortunately poorly preserved); and a
crocodile, Purussaurus sp. (based on an isolated tooth, compressed laterally, crown
strongly conical in outline, circular in cross section, and not very acutely pointed ). The
age of the Rio Yuca Formation has been an object of discussion in the literature with age
estimates ranging from early Miocene to Pliocene. The presence of cf. Nesodon and a
pollen assemblages attributable to the Verrutricolporites rotundiporis zone strongly
suggests an early Miocene (Santacrucian SALMA) age for this Formation. Several of
these taxa are recognized for first time from Venezuela (e.g., Dasypodidae [the family
Dasypodiae has been known for a long time, it is the specific taxon based on the
osteoderm that may be new] and cf. Nesodon). If the early Miocene age of the Rio Yuca
Formations is correct, the fauna also includes the oldest records of Phractocephalus in
South America). The currently known diversity of the vertebrate assemblage of the Rio
Yuca Formation is poor compared to the coeval fauna of the Cerro La Cruz Formation
(Lara and Falcón State, Venezuela), however both localities are similar in terms of
environments indicative a humid tropical climate.
Grant Informati on
This project has been supported by FONACIT PEII2012 -456 and IVIC-1096 grants
Poster Session IV (Saturday, October 17, 2015, 4:15 - 6:15)
THE LATE CRETACEOUS LAS AGUILAS DINOSAUR GRAVEYARD,
COAHUILA, MEXICO
RIVERA-SYLVA, Héctor E., Museo del Desierto, Saltillo, Mexico; FREY, Ebe rhard,
Staatliches Museum für Naturkunde Karlsruhe, Karlsru he, Germany; STINNESBECK,
Wolfgang, Universität Heidelberg, Heidelberg, Germany; PADILLA GUTIERREZ, José
Manuel, Museo del Desierto, Saltillo, Mexico; GONZÁLEZ GONZÁLEZ, Arturo H.,
Museo del Desierto, Saltillo, Mexico; AMEZCUA TORRES, Natalia, Servicio Geológico
Mexicano, Pachuca, Mexico
The latest excavation campaign at the upper Campanian Las Aguilas locality 40 km
west of Saltillo, Mexico not only yielded a partial skeleton of a medium-sized hadrosaur,
but also skeletal remains of a n ornitho mimosaur discovered b y an amateur
palaeontologist close to our site including cranial elements that allowed for a secure
identification. A new microsite was discovered by us with abundant hadosaur bones of
several individuals, that yie lded teeth of a tyrannosaurid theropod, a pelvic fragment of a
lambeosaurine hadrosaurid, longbone fragments and a phalanx of dromaeosaurid
theropods, remains of a small bird, four different species of turtles, vertebrae of small
eusuchian crocodylians that were not longer tha n one meter, and two small plesiosaur
phalanges. Geological investigations revealed that the dinosaur remains result from 13
distinct layers, which were deposited in a rapidly oscillating delta system. The abundance
of bone material in association with dinosaur tracks and plant remains makes this site
unique and allows for a detailed reconstruction of the palaeoecology during the late
Campanian of the southernmost area of the North American continent.
Poster Session IV (Saturday, October 17, 2015, 4:15 - 6:15)
ICTITHERIUM VIVERRINUM: FIRST CARNIVORE FROM THE MIOCENE IN
KYRGYZSTAN
ROBSON, Selina, University of Oregon, Eugene, OR, United States of America, 97403;
MCLAUGHLIN, Win, University of Oregon, Eugene, OR, United States of America;
WALSH, Tommy, University of Oregon, Eugene, OR, United States of America;
HOPKINS, Samantha S., University of Oregon, Eugene, OR, United States of America
The Cenozoic terrestrial record of Kyrgyzstan has, to date, seen very little study,
with only a few publications by early Russian teams surveying regional geology.
However, tectonically-GULYHQ VHGLPHQWDWLRQ IURP WKH ULVH RI WKH 7¶LDQ 6KDQ0 RXQWDLQV
has preserved a record of the terrestrial vertebrates over the last 10-12 million years.
While age constraints are challenging in the absence of volcanic activity, this fauna is
still important to our understanding of the evolution of Asian mammals in association
with the dramatic landscape changes associated with the rise of the Tibetan Plateau.
Several of the sites reported by early Russian geologists are in the Kochkor Valley, where
we have focused our efforts. Those studies presented preliminary faunal lists, but the
specimens are not described in detail and can no longer be located in any museum or
October 2015 PROGRAM AND ABSTRACTS 203
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