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Oxalaia, Pamparaptor, Atacamatitan, Pepesuchus abstracts



From: Ben Creisler
bh480@scn.org

The abstracts for the new issue of Anais da Academia Brasileira de Ciências
for the Third Gondwanan Dinosaur Symposium on now available online:
http://www.scielo.br/scielo.php?script=sci_issuetoc&pid=0001-376520110001&ln
g=en&nrm=iso

ISSN 0001-3765.

Unfortunately, the pdf links are not yet working.


Angolatitan has already been posted with the abstract and a link to the pdf.
The new taxa already mentioned on the DML without abstracts include:

Kellner, Alexander WA.; Azevedo, Sergio A.K.; Machado, Elaine B.; Carvalho,
Luciana B. de; Henriques, Deise D.R., 2011.
A new dinosaur (Theropoda, Spinosauridae) from the Cretaceous (Cenomanian)
Alcântara Formation, Cajual Island, Brazil. 
Anais da Academia Brasileira de Ciências 83 (1): 99-108 (2011)

A new spinosaurid taxon, Oxalaia quilombensis gen. et sp. nov., is
described based on the anterior part of a snout and a fragment of a
maxilla. These specimens were collected at the Laje do Coringa site, Late
Cretaceous (Cenomanian) of the São Luis Basin. Unlike Cristatusaurus and
Suchomimus, Oxalaia quilombensis lacks serrations on the teeth. The new
species differs from Angaturama limai by having the anterior part of the
premaxillae more expanded and by lacking a sagittal premaxillary crest. It
further differs from Spinosaurus cf. S. aegyptiacus and the Algerian
spinosaurid by the rounder shape of the terminal expansion. Furthermore,
Oxalaia quilobensis has one functional tooth followed by two replacement
teeth, a feature not previously observed in theropods. Oxalaia quilombensis
appears to be more closely related to the spinosaurids found in North
Africa than to the Brazilian members of this clade and thus further
increases the diversity of these enigmatic predatory dinosaurs in this
country.

Porfiri, Juan D.; Calvo, Jorge O.; Santos, Domenica dos, 2011.
A new small deinonychosaur (Dinosauria: Theropoda) from the Late Cretaceous
of Patagonia, Argentina. 
Anais da Academia Brasileira de Ciências 83 (1): 109-116 (2011)
ISSN 0001-3765. 

Here we report on a new small deinonychosaurian theropod, Pamparaptor
micros gen. et sp. nov., from the Late Cretaceous of Patagonia, Argentina.
Pamparaptor micros exhibits a pedal structure previously unknown among
South American deinonychosaurians. The new material provides new evidence
about the morphology and taxonomic diversity of Patagonian deinonychosaurs.
Pamparaptor is the smaller non-avialae Patagonian deinonychosaur, probably
with about 0.50-0.70 meters, long. The pedal construction resembles, that
of Troodontid or basal Dromaeosaurids. Nevertheless, up to now, we
considered Pamparaptor a peculiar Patagonian Dromaeosaurid with
troodontid-like pes.


Kellner, Alexander W.A.; Rubilar-Rogers, David; Vargas, Alexander; Suárez,
Mario, 2011.
A new titanosaur sauropod from the Atacama Desert, Chile. 
Anais da Academia Brasileira de Ciências 83 (1): 211-219. 
ISSN 0001-3765.

Partial remains of a titanosaur sauropod collected in the Tolar Formation
(Upper Cretaceous) at the Atacama Desert (Antofagasta Region), northern
Chile, is described, and a new species, Atacamatitan chilensis gen. et sp.
nov., is erected. The material consists mainly of dorsal and caudal
vertebrae, part of a humerus and a femur. The presence of a titanosaur
confirms the Cretaceous age for the outcrops of red sandstone of the Tolar
Formation whose age was previously uncertain, ranging from the Upper
Cretaceous to the Paleocene. The new specimen represents the most complete
dinosaur reported for this region and one of the most complete titanosaur
known from Chile and the pacific margin of South America so far.


Campos, Diogenes A.; Oliveira, Gustavo R.; Figueiredo, Rodrigo G.; Riff,
Douglas; Azevedo, Sergio A.K.; Carvalho, Luciana B.; Kellner, Alexander
W.A., 2011.
On a new peirosaurid crocodyliform from the Upper Cretaceous, Bauru Group,
southeastern Brazil. 
Anais da Academia Brasileira de Ciências 83 (1): 317-327.
ISSN 0001-3765.

A new crocodyliform from the Upper Cretaceous (Campanian-Maastrichtian)
Presidente Prudente Formation of the Bauru Group is described based on two
almost complete skulls and mandibles. The material comes from the
"Tartaruguito" site, situated at an old railroad between the cities of
Pirapozinho and Presidente Prudente, state of São Paulo, Brazil. The new
species, Pepesuchus deiseae gen. et sp. nov., is classified in the clade
Peirosauridae on the basis of three synapomorphies: the presence of five
premaxillary teeth, the anterior two premaxillary alveoli nearly confluent,
and the oval cross-section of the jugal along the lower temporal bar. The
new taxon increases the outstanding crocodyliform diversity of the Bauru
Group, particularly of the Peirosauridae, which might turn out to be one of
the most representative clades of gondwanan mesoeucrocodylians.


Other papers include:
Sayão, Juliana M.; Saraiva, Antonio A.F.; Uejima, Angelica M.K., 2011.
New evidence of feathers in the Crato Formation supporting a reappraisal on
the presence of Aves. 
Anais da Academia Brasileira de Ciências 83 (1): 197-210.
ISSN 0001-3765.

The preservation of delicate structures such as feathers is very rare in
the paleontological record, due to the fragility of their components.
Fossil feathers have been reported from approximately 50 deposits around
the world, from the Late Jurassic to the Pleistocene. In Brazil initial
findings consisted of a primary feather of a large bird found in the
Tremembé Formation. Other occurrences are preserved in the Crato Formation,
where several symmetrical and one single asymmetrical feather was found.
Based on three new specimens and reassessing further feather occurrences we
cannot confirm the presence of volant Aves in this deposit. The presence of
an asymmetrical feather without barbules and hooks hints at the previous
existence of a flightless animal within this deposit, possibly a
flightlessness bird or a non-avian theropod. Conversely, the presence of a
feather from morphotype II present in Tyrannosauroidea, Compsognathidae,
Therizinosauroidea and Dromeosauridae, points to a non-theropod origin.
Since there are no confirmed records of birds and other feathered
archosaurs in the region to date, more evidence is required to identify the
animal from which these structures originated.


Grillo, Orlando N.; Azevedo, Sergio A.K., 2011.
Pelvic and hind limb musculature of Staurikosaurus pricei (Dinosauria:
Saurischia).
Anais da Academia Brasileira de Ciências 83 (1): 73-98.
 
The study of pelvic and hind limb bones and muscles in basal dinosaurs is
important for understanding the early evolution of bipedal locomotion in
the group. The use of data from both extant and extinct taxa placed into a
phylogenetic context allowed to make well-supported inferences concerning
most of the hind limb musculature of the basal saurischian Staurikosaurus
pricei Colbert, 1970 (Santa Maria Formation, Late Triassic of Rio Grande do
Sul, Brazil). Two large concavities in the lateral surface of the ilium
represent the origin of the muscles iliotrochantericus caudalis plus
iliofemoralis externus (in the anterior concavity) and iliofibularis (in
the posterior concavity). Muscle ambiens has only one head and originates
from the pubic tubercle. The origin of puboischiofemoralis internus 1
possibly corresponds to a fossa in the ventral margin of the pré-acetabular
iliac process. This could represent an intermediate stage prior to the
origin of a true pre-acetabular fossa. Muscles caudofemorales longus et
brevis were likely well developed, and Staurikosaurus is unique in bearing
a posteriorly projected surface for the origin of caudofemoralis brevis.


Agnolin, Federico L.; Novas, Fernando E., 2011
Unenlagiid theropods: are they members of the Dromaeosauridae (Theropoda,
Maniraptora)?. Anais da Academia Brasileira de Ciências 83 (1): 117-162.

In the present paper we analyze the phylogenetic position of the derived
Gondwanan theropod clade Unenlagiidae. Although this group has been
frequently considered as deeply nested within Deinonychosauria and
Dromaeosauridae, most of the features supporting this interpretation are
conflictive, at least. Modification of integrative databases, such as that
recently published by Hu et al. (2009), produces significant changes in the
topological distribution of taxa within Deinonychosauria, depicting
unenlagiids outside this clade. Our analysis retrieves, in contrast, a
monophyletic Avialae formed by Unenlagiidae plus Aves.


Gianechini, Federico A.; Apesteguia, Sebastian, 2011.
Unenlagiinae revisited: dromaeosaurid theropods from South América. 
Anais da Academia Brasileira de Ciências 83 (1): 163-195.

Over the past two decades, the record of South American unenlagiine
dromaeosaurids was substantially increased both in quantity as well as in
quality of specimens. Here is presented a summary review of the South
American record for these theropods. Unenlagia comahuensis, Unenlagia
paynemili, and Neuquenraptor argentinus come from the Portezuelo Formation,
the former genus being the most complete and with putative avian features.
Neuquenraptor is more incomplete and exhibits pedal features resembling
those of Unenlagia. The earliest and most complete South American
dromaeosaurid is Buitreraptor gonzalezoru, whose preserved cranial remains,
provides important data in the characterization of unenlagiines. The most
recently described,Austroraptor cabazai also with cranial remains, allows
further comparisons with Laurasian lineages and a better characterization
of unenlagiines. The possible synonymy between nenlagia and Neuquenraptor
is discussed. Additional evidences from Brazil and Colombia show that
dinosaurs with similar dentition to that of unenlagiines were present in
the whole South America. However, it is not possible to discart that these
remains may belong to other unknown maniraptoran lineages, considering the
increasing number of taxa of this group found in South America.



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