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RE: Dinosaur papers: a new hope
> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu]On Behalf Of
> Tim Williams
> Pol, D. and Powell, J.W. (2007). Skull anatomy of _Mussaurus patagonicus_
> (Dinosauria: Sauropodomorpha) from the Late Triassic of Patagonia.
> Historical Biology 19(1): 125-144.
> ABSTRACT: "The skull anatomy of _Mussaurus patagonicus_ from the Upper
> Triassic Laguna Colorada Formation is described based on a revision of the
> type material and several recently found specimens. The studied material
> include two distinct size classes of individuals. The type material consists
> of extremely young individuals whereas the new specimens are interpreted as
> juvenile or subadult individuals. The latter are significantly larger,
> having a skull approximately three times longer than the type material. The
> skull anatomy of this taxon shows derived characters shared with some basal
> sauropodomorphs and eusauropods, which are absent in other basal
> sauropodomorphs (e.g. _Thecodontosaurus_, _Plateosaurus_). These include the
> presence of an extension of the infratemporal fenestra ventral to the orbit,
> dorsal and anterior rami of quadratojugal subperpendicular to each other,
> dorsoventral expansion of dentary at mandibular symphysis, slightly
> procumbent teeth with broad serrations restricted to the apical region
> (absent in some teeth). Differences among the studied specimens helps to
> understand the early ontogenetic changes occurring in this basal
> sauropodomorph, revealing major changes in the rostral and temporal
> Sereno, P.C. (2007). The phylogenetic relationships of early dinosaurs: a
> comparative report. Historical Biology 19(1): 145-155.
> ABSTRACT: "Surprising new anatomical information has come to light for the
> early dinosaurs _Eoraptor lunensis_ and _Herrerasaurus ischigualastensis_.
> _Eoraptor_ has a mid mandibular jaw joint, and _Herrerasaurus_ has a
> promaxillary fenestra at the anterior end of the antorbital fossa. Initial
> cladistic interpretation placed _Herrerasaurus_ outside Dinosauria. Since
> then, _Eoraptor_ and _Herrerasaurus_ have been placed at the base of
> Saurischia or within Theropoda in two large-scale quantitative analyses. A
> comparative approach is taken here to show, first, that character choice is
> a major factor behind differing results; only half of the character data
> critical for each interpretation is incorporated into the opposing analysis.
> In that shared portion of data, furthermore, nearly 40 percent of character
> state scores vary for identical, or comparable, ingroup taxa. Resolving
> these conflictive interpretations is clearly where future progress will be
> made in understanding early dinosaur phylogenesis."
I would greatly appreciate the Mussaurus and Sereno papers, myself...
Thomas R. Holtz, Jr.
Senior Lecturer, Vertebrate Paleontology
Department of Geology Director, Earth, Life & Time Program
University of Maryland College Park Scholars
Building 237, Room 1117
College Park, MD 20742
Phone: 301-405-4084 Email: firstname.lastname@example.org
Fax (Geol): 301-314-9661 Fax (CPS-ELT): 301-405-0796