|
Not many dinosaur-related talks were presented on
Thursday.
Atanassov, 2001. Two new archosauromorphs from the
Late Triassic of Texas. JVP 21(3) 30A.
One is a tanystropheid, the other an archosaurian
pterosaur ancestor. Quite intriguing, but not dinosaurian. The point
I wanted to make here was that some of the supposed tanystropheid cervical
vertebrae are near identical to those of Protoavis, even more so than
megalancosaurs'. Did anyone else notice this?
Paul, 2001. Increasing evidence for an arboreal
origin of dinosaur-avian flight and for losses of flight in post-urvogel
dinosaurs. JVP 21(3) 88A.
Paul had a lot of characters supposedly present in
deinonychosaurs, troodontids and oviraptorosaurs, but absent in
Archaeopteryx. I regret not photographing the character lists in his
poster that support this, but most seemed to be gradational characters that
would be hard to code. He argued basal deinonychosaurs (Sinornithosaurus,
Microraptor) are more bird-like than dromaeosaurids, thus showing the clade is
secondarily flightless. I would argue his "basal deinonychosaurs" are
basal avialans, but I do think there is a strong possibility maniraptorans are
secondarily flightless, just not more derived than Archaeopteryx. For
instance, why is the absence of ossified uncinate processes in Archaeopteryx
indicative of a basal position when the pygostylian Protopteryx lacks them
too? An interesting fact was that Sinornithosaurus and cf.
Sinornithosaurus have an expanded manual phalanx II-1, like pygostylians and
more derived than Archaeopteryx. Intriguing. Great pictures of
Sinornithosaurus and Microraptor too- the latter looked like my restoration but
a billion times better. His cladogram had the following topology, missing
several groups I couldn't copy down in time.
|-+-Abelisauridae
| `-Megalosauridae `-+-Yangchuanosaurus `-+-+-Coelurus | `-Ornitholestes `-+-Archaeopteryx `-+-+-Sinornithosaurus | `-+-Velociraptor | `-Deinonychus `-+-Troodontidae `-+-Oviraptorosauria `-Pygostylia The posters were quite numerous though. Here
are some, including a few not shown.
Maderson, Hillenius, Martin, Ruben, Jones and
Geist, 2001. Reconstructing Longisquama skin. JVP 21(3) 76A.
The most amusing abstract by far. The poster
was decorated with colorful spiral graphs and frowning faces. Apparently
they realize they will never convince anyone Longisquama has feathers, so now
they are termed "parafeathers". Not only this, but Longisquama also is
said to have parasheaths, paracalami, pararachis, parabarbs and paraveins.
Parabelievable.
Titus, Gillette and Albright, 2001. Significance of
an articulated lambeosaurine hadrosaur from the Kaiparowits Formation (Upper
Cretaceous), Southern Utah. JVP 21(3) 108A.
An unidentified lambeosaurine was found in the Late
Campanian Kaiparowits Formation of Utah. It includes a sacrum,
thirty-three caudals with chevrons, in situ ossified tendons, a possible
ischium, an astragalus and several pedal elements including a
metatarsal.
Prieto-Marquez, 2001. Osteology and variation of
Brachylophosaurus canadensis (Dinosauria, Hadrosauridae) from the Upper
Cretaceous Judith River Formation of Montana. JVP 21(3) 90A.
A complete adult skeleton and over 1300 specimens
in a bonebed show Brachylophosaurus is diagnosed by- subrectangular skull with
deep snout; nasals developed into a paddle-shaped solid crest that extends
caudodorsally; nasals with an anteroposteriorly-oriented groove terminating in
an elongate foramen, medial to the prefrontal; prefrontal projected posteriorly,
resting dorsomedially over the anterior postorbital process and ventromedially
under the nasal; ventrally projected semicircular flange on jugal; surface of
frontal between nasal and postorbital joint depressed; short
exoccipital-supraoccipital posterodorsal to the foramen magnum; very long and
slender forearm. B. goodwini is a junior synonym of B.
canadensis.
Wagner and Lehman, 2001. A new species of
Kritosaurus from the Cretaceous of Big Bend National Park, Brewster County,
Texas. JVP 21(3) 110A-111A.
A new specimen (TMM 42452) from the Campanian Aguja
Formation of Texas includes a maxilla, nasals, a jugal, a quadratojugal, partial
dentaries, other cranial elements and a manus. It is distinguished from
other Kritosaurus species by a wide, scoop-shaped dentary symphysis, W-shaped in
anterior view. Wagner's cladogram was something like
|-+-|-Kritosaurus notabilis
| | |-K. navajovius | | |-K. laticaudus | | `-K. sp. nov. | `-Hadrosaurus `-+-Edmontosaurus `-+-Brachylophosaurus `-+-Saurolophus `-Lambeosaurinae ... though I recall he said two of the hadrosaurine
groups should have been together, and the topology above was a typo in that
regard.
Godefroit and Bolotsky, 2001. The Maastrichtian
hadrosaurid fauna from the Amur region (China and Russia). JVP 21(3)
55A.
Amurosaurus riabinini from the Late Maastrichtian
Blagoveschensk of Russia is a "helmet crested" lambeosaurine sister to the
(Corythosaurus, Lambeosaurus (Parasaurolophus, Charonosaurus)) clade. A
new hadrosaurine taxon from Blagoveschensk is sister to the (Edmontosaurini,
Saurolophini) clade. Also, a new species of Amurosaurus and a new
hadrosaurine are reported from the Late Maastrichtian Kundur of
Russia.
Hamm and Everhart, 2001. Notes on the occurence of
nodosaurs (Ankylosauridae) in the Smoky Hill Chalk (Upper Cretaceous) of Western
Kansas. JVP 21(3) 58A.
A radius and ulna from a juvenile nodosaur were
found in the Smoky Hill Chalk Member of the Niobrara Chalk (Middle
Santonian). They are about half the size of Niobrarasaurus, indicating an
individual three meters long. Other nodosaurs from the formation include
Niobrarasaurus (MU 650 VP), Hierosaurus (YPM 1847), a pair of scutes (YPM 55419)
and a partial skeleton (KUVP 25150). All are from the Late Coniacian,
except the last, which is Middle Santonian.
Parsons and Parsons, 2001. Description of a new
skull of Sauropelta cf. S. edwardsi Ostrom, 1970 (Ornithischia: Ankylosauria).
JVP 21(3) 87A.
A new skull (MOR 1073) from the Cloverly Formation
of Montana is described, giving the first good cranial information for
Sauropelta. The posterior portion matches with AMNH 3035, a partial
Sauropelta skull, but there are some differences from referred cranial fragments
of the latter genus.
Vickaryous and Russell, 2001. New information of
the skull of the ankylosaurian dinosaur Euoplocephalus tutus Lambe (1902) and a
review of Ankylosauria cranial osteology. JVP 21(3) 110A.
An in depth examination of Euoplocephalus' skull,
compared to other ankylosaurs as well. It is most similar to Ankylosaurus
in cranial morphology and there are no significant differences from skulls
described as other taxa (Scolosaurus, Dyoplosaurus, etc.).
Ott and Buckley, 2001. First report of
Protoceratopsidae from the Hell Creek Formation. JVP 21(3) 86A.
A partial skull of a juvenile Leptoceratops is
reported from the Hell Creek Formation (Late Maastrichtian) of
Montana.
Schwimmer and Kiernan, 2001. Eastern Late
Cretaceous theropods in North America and the crossing of the Interior Seaway.
JVP 21(3) 99A.
There is a Middle Campanian tyrannosauroid from
Alabama, more basal than albertosaurines and tyrannosaurines. There is
also an Early Campanian velociraptorin-type tooth from Alabama.
Senter and Hutchinson, 2001. New information on the
skeleton of the theropod Segisaurus halli. JVP 21(3) 100A.
There's a lot of new information on the poster, but
the authors asked me not to post it on the internet, so I'll only reveal what's
in the abstract. Segisaurus has been re-prepared, showing a furcula in
articulation with the coracoids, no postcervical pleurocoels, small anterior
trochantor, large fourth trochantor, trochanteric shelf and thin-walled
long bones. Sutural fusion and histology show it is adult, so the lack of
pelvic fusion is not ontogenetic. The abstract says a phylogenetic
analysis shows it to be a non-coelophysid coelophysoid, but it had a different
position in the poster...
Rinehart, Lucas and Heckert, 2001. Preliminary
statistical analysis defining the juvenile, robust and gracile forms of the
Triassic dinosaur Coelophysis. JVP 21(3) 93A.
Probability plots comparing biometric data show
Coelophysis can be separated into juvenile, gracile and robust forms.
Interestingly, there are also three forms of the Shake-V-Bake coelophysoid,
Syntarsus rhodesiensis and Allosaurus.
However...
Gay, 2001. Evidence for sexual dimorphism in the
Early Jurassic theropod dinosaur, Dilophosaurus and a comparison with other
related forms. JVP 21(3) 53A.
He finds that variation in Dilophosaurus is
individual, not sexual. Goes to show you can't expect all theropods to
work out the same way...
Smith, Lamanna, Dodson, Attia and Lacovara, 2001.
Evidence of a new theropod from the Late Cretaceous of Egypt. JVP 21(3)
102A.
Several teeth from the Bahariya Formation
(Cenomanian) of Egypt are quite small (CBL* 7.5 mm) and have serration
morphologies and width/length ratios similar to abelisaurids.
* CBL basically is the same as FABL
Carr and Williamson, 2001. Resolving tyrannosaurid
diversity: Skeletal remains referred to Aublysodon belong to Tyrannosaurus rex
and Daspletosaurus. JVP 21(3) 38A.
Aublysodon molnari is referred to Tyrannosaurus rex
based on synapomorphies and quantitative growth series. The supposed
serrationless premaxillary tooth is actually the first maxillary tooth preserved
in situ. The Kirtland Formation Aublysodon is Daspletosaurus based on
postorbital morphology. The premaxillary tooth is serrated. The
holotype of Aublysodon mirandus is probably indeterminate and lost.
The ones I found most interesting (Iren Debasu
Avimimus, Shuvuuia, Nothronychus braincase, basal tyrannosauroids), complete
with photos, will come tomorrow.
Mickey
Mortimer |