New Papers of the Ya-Ya Sisterhood

["Jerry D. Harris" <jharris@dixie.edu>]

Two new papers available free on-line at http://pubs.usgs.gov/of/2007/1047:


Smith, N.D., Makovicky, P.J., Pol, D., Hammer, W.R., and Currie, P.J. 2007. 
The dinosaurs of the Early Jurassic Hanson Formation of the central 
Transantarctic Mountains: phylogenetic review and synthesis; pp. 1-5 in 
Cooper, A., Raymond, C., and Team, I.E. (eds.), Antarctica: a Keystone in a 
Changing World -- Online Proceedings for the Tenth International Symposium 
on Antarctic Earth Sciences. U.S. Geological Survey Open-File Report 
2007-1047, SRP 003. U.S. Geological Survey, Washington, D.C.

ABSTRACT: The Hanson Formation of the Central Transantarctic Mountains has 
yielded a diverse Early Jurassic terrestrial fauna, which includes the 
nearly complete theropod dinosaur, Cryolophosaurus ellioti, and a 
fragmentary basal sauropodomorph dinosaur. The Hanson Formation dinosaurs 
are important for understanding early dinosaur evolution because: 1) they 
preserve a mosaic of morphological traits that render them useful for 
interpreting poorly known parts of the dinosaur evolutionary tree; 2) they 
are from the Early Jurassic, a critical period in early dinosaur evolution 
about which knowledge is scant; and 3) they are the only known Early 
Jurassic dinosaurs from Antarctica, making them particularly valuable for 
understanding patterns of biotic interchange during this time. Recent 
research suggests that Cryolophosaurus belongs to a geographically 
widespread clade of mid-sized, Early Jurassic theropods with cranial crests 
that includes Dilophosaurus wetherilli, 'Dilophosaurus' sinensis, and 
Dracovenator, and renders Coelophysoidea sensu lato non-monophyletic. The 
Antarctic sauropodomorph represents a distinct taxon that is a member of a 
similarly diverse massospondylid clade. This taxon shares a number of 
features with more derived sauropodomorphs, and provides additional evidence 
for the paraphyly of Prosauropoda. The phylogenetic relationships of the 
Antarctic dinosaurs are also consistent with a pattern of worldwide faunal 
homogeneity between Early Jurassic continental biotas. Furthermore, these 
analyses support a "ladder-like" arrangement for basal theropod and basal 
sauropodomorph phylogeny, suggesting that these groups passed through 
"coelophysoid" and "prosauropod" stages of morphological organization early 
in their respective evolutionary histories.



Case, J.A., Martin, J.E., and Reguero, M. 2007. A dromaeosaur from the 
Maastrichtian of James Ross Island and the Late Cretaceous Antarctic 
dinosaur fauna; pp. 1-4 in Cooper, A., Raymond, C., and Team, I.E. (eds.), 
Antarctica: a Keystone in a Changing World -- Online Proceedings for the 
Tenth International Symposium on Antarctic Earth Sciences. U.S. Geological 
Survey Open-File Report 2007-1047, SRP 083. U.S. Geological Survey, 
Washington, D.C.

ABSTRACT: The recovery of material of a small theropod from the Early 
Maastrichtian, Cape Lamb Member of the Snow Hill Island Formation is an 
unusual occurrence from primarily marine sediments. The pedal morphology of 
the specimen that includes a Metatarsal II with a lateral expansion caudal 
to Metatarsal III, a third metatarsal that is proximally narrow and distally 
wide, a Metatarsal III with a distal end that is incipiently ginglymoidal 
and a second pedal digit with sickle-like ungual are all diagnostic of a 
theropod that belongs to the family of predatory dinosaurs, the 
Dromaeosauridae. Yet this Antarctic dromaeosaur retains plesiomorphic 
features in its ankle and foot morphology. As new dromaeosaur species are 
being recovered from the mid-Cretaceous of South America and the retention 
of primitive characters in the Antarctic dromaeosaur, a new biogeographic 
hypothesis on dromaeosaur distribution has been generated. Gondwanan 
dromaeosaurs are not North America immigrants into South America and 
Antarctica; rather they are the relicts of a cosmopolitan dromaeosaur 
distribution, which has been separated by the vicariant break up of Pangea 
and created an endemic clade of dromaeosaurs in Gondwana.



In the same volume, for those interested, a paper on a Late Cretaceous flora 
from the Shetland Islands (paper 081) and a juvenile Antarctic elasmosaurid 
(paper 066).  Some papers concerning mostly Permian stuff, too.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jerry D. Harris
Director of Paleontology
Dixie State College
Science Building
225 South 700 East
St. George, UT  84770   USA
Phone: (435) 652-7758
Fax: (435) 656-4022
E-mail: jharris@dixie.edu
and     dinogami@gmail.com
http://cactus.dixie.edu/jharris/

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