Ben Creisler | 17 Apr 19:44 2014
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Rhamphorhynchoid pterosaur tracks identified at Crayssac in France (news story)

From: Ben Creisler
bcreisler <at> gmail.com

There has been some controversy about alleged tracks from
rhamphorhynchoid pterosaurs--pterodactyloid pterosaur tracks are well
documented and scientifically accepted.

The following news story in French indicates that clear evidence of
tracks left by a rhamphorhynchoid may have been found at Crayssac in
France:

http://www.ladepeche.fr/article/2014/04/17/1865073-pterosaures-a-crayssac-nous-sommes-la-dans-une-joaillerie.html

The tracks of a rhamphorhynchoid pterosaur (nicknamed Dimitri) found
at Crayssac are being studied with light projected at a low angle to
bring out the details and are yet to described.

These are reportedly the first confirmed tracks of a rhamphorhynchoid
and show that it walked quadrupedally like a pterodactyloid.

Principale différence visible en lumière rasante sous les projecteurs
: le rhamphorhynchoïde possède cinq orteils dont un à 90°...

[Main difference visible in raking-angle light from the beams: the
rhamphorhychoid has five toes, one of which is at 90°...]

Ben Creisler | 17 Apr 18:07 2014
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Vertebrates from Late Triassic Thecodontosaurus-bearing rocks in England

From: Ben Creisler
bcreisler <at> gmail.com

A new online paper:

Davide Foffa, David I. Whiteside, Pedro A. Viegas & Michael J. Benton (2014)
Vertebrates from the Late Triassic Thecodontosaurus-bearing rocks of
Durdham Down, Clifton (Bristol, UK).
Proceedings of the Geologists' Association (advance online publication)
http://dx.doi.org/10.1016/j.pgeola.2014.02.002
http://www.sciencedirect.com/science/article/pii/S001678781400008X

Since the discovery of the basal sauropodomorph dinosaur
Thecodontosaurus in the 1830s, the associated fauna from the Triassic
fissures at Durdham Down (Bristol, UK) has not been investigated,
largely because the quarries are built over. Other fissure sites
around the Bristol Channel show that dinosaurs represented a minor
part of the fauna of the Late Triassic archipelago. Here we present
data on microvertebrates from the original Durdham Down fissure rocks,
which considerably expand the taxonomic diversity of the island fauna,
revealing that it was dominated by the sphenodontian Diphydontosaurus,
and that archosauromorphs, including sphenosuchian crocodylomorphs,
coelophysoid theropods, and the basal sauropodomorph Thecodontosaurus,
were diverse. Importantly, a few fish teeth provide new information
about the debated age of the fissure deposit, which is identified as
lower Rhaetian. Thecodontosaurus had been assigned an age range over
20-25 Myr of the Late Triassic, so this narrower age determination
(209.5-204 Myr) is important for studies of early dinosaurian
evolution.

(Continue reading)

Ben Creisler | 17 Apr 18:00 2014
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Avian extinction at end of Cretaceous

From: Ben Creisler
bcreisler <at> gmail.com

A new paper:

Alan Feduccia (2014)
Avian extinction at the end of the Cretaceous: Assessing the magnitude
and subsequent explosive radiation.
Cretaceous Research 50: 1-15
http://dx.doi.org/10.1016/j.cretres.2014.03.009
http://www.sciencedirect.com/science/article/pii/S0195667114000494

Debate on the magnitude of Cretaceous extinctions and timing of modern
bird origins has sharply coalesced over the past two decades into
contested models, gradualistic or explosive. Molecular clocks,
bolstered by phylogenetic, biogeographic, and vicariance models,
support an Early Cretaceous origin for birds and mammals over 100
million years ago. Yet, although numerous new Chinese fossils of
archaic ornithurine birds have been discovered in the Jehol Biota of
the Early Cretaceous of China, none shows close affinity to modern
neornithines; it is not until the latest Cretaceous when some fossils
show more advanced ornithurine morphology, and are possibly
Neornithes. In contrast to mass survival scenarios, most
paleontological evidence appears to support an explosive radiation
following the Cretaceous-Paleogene (K-Pg) mass extinction event,
closely paralleling the geometry of mammal evolution. Gradualistic
models ignore recent evidence of cataclysmic worldwide events
following the impact event. How could mass survival of the
environmentally sensitive birds have occurred following cosmopolitan
environmental destruction, when other terrestrial vertebrates,
(Continue reading)

Ben Creisler | 17 Apr 17:41 2014
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Gargantuavis (Cretaceous bird) bone microstructure

From: Ben Creisler
bcreisler <at> gmail.com

A new online paper:

Anusuya Chinsamy, Eric Buffetaut, Aurore Canoville & Delphine Angst (2014)
Insight into the growth dynamics and systematic affinities of the Late
Cretaceous Gargantuavis from bone microstructure.
Naturwissenschaften (advance online publication)
DOI: 10.1007/s00114-014-1170-6
http://link.springer.com/article/10.1007/s00114-014-1170-6

Enigmatic avialan remains of Gargantuavis philoinos from the
Ibero-Armorican island of the Late Cretaceous European archipelago
(Southern France) led to a debate concerning its taxonomic affinities.
Here, we show that the bone microstructure of Gargantuavis resembles
that of Apteryx, the extinct emeids and Megalapteryx from New Zealand,
and indicates that like these slow-growing terrestrial birds, it took
several years to attain skeletal maturity. Our findings suggest that
the protracted cyclical growth in these ornithurines may have been in
response to insular evolution.

Ben Creisler | 16 Apr 23:13 2014
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Eocasea, new caseid synapsid from Late Pennsylvanian of Kansas

From: Ben Creisler
bcreisler <at> gmail.com

New in PLoS ONE:

Robert R. Reisz & Jörg Fröbisch (2014)
The Oldest Caseid Synapsid from the Late Pennsylvanian of Kansas, and
the Evolution of Herbivory in Terrestrial Vertebrates.
PLoS ONE 9(4): e94518.
doi:10.1371/journal.pone.0094518
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0094518

The origin and early evolution of amniotes (fully terrestrial
vertebrates) led to major changes in the structure and hierarchy of
terrestrial ecosystems. The first appearance of herbivores played a
pivotal role in this transformation. After an early bifurcation into
Reptilia and Synapsida (including mammals) 315 Ma, synapsids dominated
Paleozoic terrestrial vertebrate communities, with the herbivorous
caseids representing the largest vertebrates on land. Eocasea martini
gen. et sp. nov., a small carnivorous caseid from the Late
Carboniferous, extends significantly the fossil record of Caseidae,
and permits the first clade-based study of the origin and initial
evolution of herbivory in terrestrial tetrapods. Our results
demonstrate for the first time that large caseid herbivores evolved
from small, non-herbivorous caseids. This pattern is mirrored by three
other clades, documenting multiple, independent, but temporally
staggered origins of herbivory and increase in body size among early
terrestrial tetrapods, leading to patterns consistent with modern
terrestrial ecosystem.
==
(Continue reading)

Ben Creisler | 16 Apr 22:34 2014
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Basal dinosauriform and theropod dinosaurs from Late Triassic of Poland

From: Ben Creisler
bcreisler <at> gmail.com

A new online paper:

Grzegorz Niedźwiedzki, Stephen L. Brusatte, Tomasz Sulej, and Richard
J. Butler (2014)
Basal dinosauriform and theropod dinosaurs from the mid–late Norian
(Late Triassic) of Poland: implications for Triassic dinosaur
evolution and distribution.
Palaeontology (advance online publication)
DOI: 10.1111/pala.12107
http://onlinelibrary.wiley.com/doi/10.1111/pala.12107/abstract

The rise of dinosaurs during the Triassic is a widely studied
evolutionary radiation, but there are still many unanswered questions
about early dinosaur evolution and biogeography that are hampered by
an unevenly sampled Late Triassic fossil record. Although very common
in western North America and parts of South America, dinosaur (and
more basal dinosauriform) remains are relatively rare in the Upper
Triassic deposits of Europe, making any new discoveries critically
important. One of the most diverse dinosauriform assemblages from
Europe comes from the Poręba site in Poland, a recently described
locality with exposures of the Zbąszynek Beds, which have a
palynomorph assemblage characteristic for the mid–late Norian in the
biostratigraphic schemes of the Germanic Basin. Using a
synapomorphy-based approach, we evaluate several isolated
dinosauriform specimens from Poręba. This assemblage includes a
silesaurid, a herrerasaurid and remains of another type of theropod
(potentially a neotheropod). The Poręba herrerasaurid is the first
(Continue reading)

Ben Creisler | 16 Apr 22:32 2014
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Origins of Dinosauria (free pdf)

From: Ben Creisler
bcreisler <at> gmail.com

A new online paper in open access:

Max C. Langer (2014)
The origins of Dinosauria: much ado about nothing.
Palaeontology (advance online publication)
DOI: 10.1111/pala.12108
http://onlinelibrary.wiley.com/doi/10.1111/pala.12108/abstract
free pdf:
http://onlinelibrary.wiley.com/doi/10.1111/pala.12108/pdf

Research this century has greatly improved our knowledge of the origin
and early radiation of dinosaurs. The unearthing of several new
dinosaurs and close outgroups from Triassic rocks from various parts
of the world, coupled with improved phylogenetic analyses, has set a
basic framework in terms of timing of events and macroevolutionary
patterns. However, important parts of the early dinosauromorph
evolutionary history are still poorly understood, rendering uncertain
the phylogenetic position of silesaurids as either non-dinosaur
Dinosauriformes or ornithischians, as well as that of various early
saurischians, such as Eoraptor lunensis and herrerasaurs, as either
noneusaurischians or members of the sauropodomorph or theropod
lineages. This lack of agreement in part derives from a patchy
distribution of traits among early members of the main dinosauromorph
lineages and requires a more meticulous assessment of characters and
homologies than those recently conducted. Presently, the oldest
uncontroversial dinosaur records come from Late Triassic (Carnian)
rocks of South America, southern Africa and India, hinting at a
(Continue reading)

Ben Creisler | 16 Apr 17:09 2014
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Birdlike egg from Cretaceous of Zhejiang Province, China

From: Ben Creisler
bcreisler <at> gmail.com

A new online paper:

Shukang Zhang, Xingsheng Jin, Jingmai K. O'Connor, Min Wang & Junfang Xie (2014)
A new egg with avian egg shape from the Upper Cretaceous of Zhejiang
Province, China.
Historical Biology (advance online publication)
DOI:10.1080/08912963.2014.902451
http://www.tandfonline.com/doi/full/10.1080/08912963.2014.902451#.U06Z3_ldXeI

A new egg is described from the Upper Cretaceous lacustrine deposit of
the Chichengshan Formation in the Tiantai Basin, Zhejiang Province,
southeast China. The new specimen shares eggshell micro-features with
members of the oofamily Stalicoolithidae, Paraspheroolithus of the
oofamily Spheroolithidae and Mosaicoolithus (oofamily indet.), with
barrel-shaped cones, prolatocanaliculate pore system, horizontal
accretion lines and light stripes throughout the eggshell. However,
the new egg differs from the aforementioned ootaxa by its small size
and asymmetrical shape, revealing new morphological variation among
eggs with microstructure similar to that of Paraspheroolithus,
Mosaicoolithus and Stalicoolithidae. We refer the new egg to a new
oogenus and oospecies, thus increasing the diversity of the Tiantai
Basin oofauna. The Tiantai Basin has yielded a variety of dinosaur
eggs and one turtle clutch. Comparatively, the new egg is surprisingly
small and ovoid, a morphology usually associated with avian eggs,
although the absence of a squamatic layer excludes the egg from being
referred to this group.
==
(Continue reading)

Ben Creisler | 16 Apr 17:08 2014
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Giant fossil crocodyliform "death roll" use

From: Ben Creisler
bcreisler <at> gmail.com

A new online paper:

Rudemar Ernesto Blanco, Washington W. Jones & Joaquín Villamil (2014)
The ‘death roll’ of giant fossil crocodyliforms (Crocodylomorpha:
Neosuchia): allometric and skull strength analysis.
Historical Biology (advance online publication)
DOI:10.1080/08912963.2014.893300
http://www.tandfonline.com/doi/full/10.1080/08912963.2014.893300#.U06ZEvldXeI

In the evolution of crocodylomorphs, there were at least three
giant-dimension genera: Deinosuchus from late Cretaceous of North
America, Sarcosuchus from middle Cretaceous of Africa and South
America, and Purussaurus from Miocene of South America. It has been
suggested that these predators could have fed on very large prey as
dinosaurs and megamammals. The ‘death roll’ is a spinning manoeuver
executed to subdue and dismember large prey; therefore, it has been
previously suggested that giant crocodylomorphs may have used this
manoeuver. However, this manoeuver can generate torsional stresses in
the skull. We propose a biomechanical model to estimate the capability
of a crocodylomorphs for withstanding this torsional stresses. Our
results show a good correlation between a ‘death roll’ capability
indicator and the feeding categories related with the actual use of
‘death roll’ in 16 living species. Here, for the first time, we
propose a biomechanical approach of the implications of ‘death roll’
in fossil crocodylomorphs. We suggest that Deinosuchus and Purussaurus
were able to execute death roll over dinosaurs and large mammals,
respectively, but Sarcosuchus probably was not. We also found some
(Continue reading)

Ben Creisler | 16 Apr 17:00 2014
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Bonatitan (Cretaceous titanosaur from Argentina) redescribed

From: Ben Creisler
bcreisler <at> gmail.com

A new online paper:

L. Salgado, P.A. Gallina & A. Paulina Carabajal (2014)
Redescription of Bonatitan reigi (Sauropoda: Titanosauria), from the
Campanian–Maastrichtian of the Río Negro Province (Argentina).
Historical Biology (advance online publication)
DOI:10.1080/08912963.2014.894038
http://www.tandfonline.com/doi/full/10.1080/08912963.2014.894038#.U06ZP_ldXeI

The titanosaur sauropod Bonatitan reigi is redescribed. The material
collected, originally interpreted as pertaining to two different
individuals, is reorganised in five individuals, and the original type
specimen is separated into three different individuals. One of the
braincases is designated as a new type specimen. Some materials are
described by the first time (sacral ribs, distal caudal, chevrons,
metacarpals, astragalus and metatarsals), others reinterpreted as
different bones (‘ulna’ and ‘radius’). The diagnosis of B. reigi is
emended, removing some of the original characters (longitudinal groove
located on the suture between the parietals that continues posteriorly
over the supraoccipital to the foramen magnum) and adding some new
(small paired pits on the frontals and posterior ridge of the
metacarpal IV). The phylogenetic analysis does not support B. reigi as
a member of the Saltasaurinae, but rather as a basal member of a broad
clade of sauropods that in turn is recovered as the sister group of
the Saltasauridae.

(Continue reading)

Ben Creisler | 16 Apr 06:29 2014
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Laramidia dinosaurs in National Geographic and other news

From: Ben Creisler
bcreisler <at> gmail.com

Some recent news items:

May National Geographic article about Laramidia and its dinosaurs

http://ngm.nationalgeographic.com/2014/05/utah-dinosaurs/miller-text

News release:

http://unews.utah.edu/news_releases/hunting-our-history/

===

Wankel T. rex arrives at Smithsonian

http://news.nationalgeographic.com/news/2014/04/140415-tyrannosaurus-rex-arrival-wankel-smithsonian-paleontology-science/

http://www.washingtonpost.com/local/t-rex-fossils-to-arrive-at-smithsonian-museum-today/2014/04/14/1a8c39aa-c412-11e3-b195-dd0c1174052c_story.html

==

"Dakota" hadrosaur mummy purchase plans by state of North Dakota

http://www.washingtontimes.com/news/2014/apr/15/nd-dealing-to-keep-dinosaur-mummy-in-bismarck/

===

T. rex neck strength
(Continue reading)


Gmane