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Online (sort of...): the latest issue of JVP, introducing Silesaurus opolensis



Greetings,

For the last couple of days, the text and some of the figures (but not the
pdfs) of the lastest issue of the Journal of Vertebrate Paleontology has
been online
(http://www.bioone.org/bioone/?request=get-toc&issn=0272-4634&volume=023&iss
ue=03). I was waiting for the figures to be out to comment, but thought I'd
get the initial announcement out.

The cover girl is Silesaurus opolensis, described in:
Dzik, J. 2003. A BEAKED HERBIVOROUS ARCHOSAUR WITH DINOSAUR AFFINITIES FROM
THE EARLY LATE TRIASSIC OF POLAND. Journal of Vertebrate Paleontology: Vol.
23, No. 3, pp. 556?574.

There was some earlier speculation about this form on the list (as far back
as October of last year). As Dzik describes it, this is a large
non-dinosaurian dinosauromorph, about 2.3 m long.  It is restored as a
long-necked quadruped, with rather gracile forelimbs. Its teeth are conical,
grooved, and variably serrated. The sides of the teeth are worn, suggesting
herbivory. The tip of the dentary is toothless, and the anatomy suggests it
was covered by a beak. However, there is no sign of a predentary. Most of
the postcranium is known.

Parts of many individuals are represented. As mentioned previously on this
list, the specimen comes from the early Carnian; as recent discoveries seem
to indicate the presence of Ladinian dinosaurs, this is not the oldest
dinosaur as earlier announced. Furthermore, Dzik does not consider this a
dinosaur at all, but instead a dinosauromorph closer to Dinosauria than was
Pseudolagosuchus.

It lacks the enlarged deltopectoral crest and epiphyses on the cervical
vertebra of Dinosauria. However, it has a brevis shelf, an ischium with a
slender shaft, a femur with reduction of the tuberosity that laterally
bounds the ligament of the femoral head, a prominent lesser trochanter, an
overlap of the ascending process of the astragalus with the tibia, and a
concave proximal articular surface for the reception of the distal end of
the fibula on the calcaneum: all these were previously discovered to be
dinosaurian synapomorphies. Its acetabulum is closed.

Dzik doesn't actually do a phylogenetic analysis of this animal, but does
suggest a couple of alternative positions for it to the favored hypothesis:
1) that it is an ornithischian basal to all currently known; or 2) that it
is the sister taxon to an Ornithischia-Sauropodomorpha clade (whoa,
Phytodinosauria redux!).

Option 1 may be less crazy than it sounds, as basal members of saurischian
lineages (Saturnalia, Guabiasaurus, Herrerasauridae, Eoraptor) seem to have
muddied up what used to be perfectly good dinosaurian synapomorphies...

More later.

Other papers of dinosaurian (and Mesozoic reptile) interest are:
RELATIONSHIPS BETWEEN EUROPEAN AND INDIAN DINOSAUR EGGS AND EGGSHELLS OF THE
OOFAMILY MEGALOOLITHIDAE. MONIQUE VIANEY-LIAUD, ASHU KHOSLA, and GERALDINE
GARCIA, pages 575?585.

DINOSAURS FROM THE EARLY CRETACEOUS MURTOI FORMATION IN BURYATIA, EASTERN
RUSSIA. ALEXANDER AVERIANOV, ALEXEI STARKOV, and PAVEL SKUTSCHAS, pages
586?594.

THE EVOLUTION OF MANUS SHAPE IN SAUROPOD DINOSAURS: IMPLICATIONS FOR
FUNCTIONAL MORPHOLOGY, FORELIMB ORIENTATION, AND PHYLOGENY. MATTHEW F.
BONNAN, pages 595?613.

THE ANHINGAS (AVES: ANHINGIDAE) FROM THE UPPER TERTIARY (MIOCENE?PLIOCENE)
OF SOUTHWESTERN AMAZONIA. HERCULANO M. F. ALVARENGA and EDSON GUILHERME,
pages 614?621.

HISTOLOGY OF TOOTH ATTACHMENT TISSUES IN THE LATE CRETACEOUS MOSASAURID
PLATECARPUS. M. W. CALDWELL, L. A. BUDNEY, and D. O. LAMOUREUX, pages
622?630.

OPHTHALMOSAURIA (ICHTHYOSAURIA) FOREFIN FROM THE AALENIAN-BAJOCIAN BOUNDARY
OF MENDOZA PROVINCE, ARGENTINA. MARTA S. FERNÁNDEZ, pages 691?694.

A LARGE ORNITHOMIMID PES FROM THE LOWER CRETACEOUS OF THE MAZONGSHAN AREA,
NORTHERN GANSU PROVINCE, PEOPLE?S REPUBLIC OF CHINA. MICHAEL D. SHAPIRO,
HAILU YOU, NEIL H. SHUBIN, ZHEXI LUO, and JASON PHILIP DOWNS, pages 695?698.

ABNORMAL, MULTILAYERED EGGSHELL IN BIRDS: IMPLICATIONS FOR DINOSAUR
REPRODUCTIVE ANATOMY. FRANKIE D. JACKSON and DAVID J. VARRICCHIO, pages
699?702.

DREPANOSAURID (REPTILIA: DIAPSIDA) REMAINS FROM A LATE TRIASSIC FISSURE
INFILLING AT CROMHALL QUARRY (AVON, GREAT BRITAIN). SILVIO RENESTO and
NICHOLAS C. FRASER, pages 703?705.

CORRECTION: HANSSUESIA, THE CORRECT GENERIC NAME FOR ?HANSSUESSIA? SULLIVAN,
2003. , pages 714?714.

RAPID COMMUNICATION: A NEW TRIASSIC OWENETTID PARAREPTILE AND THE MOTHER OF
MASS EXTINCTIONS. SEAN P. MODESTO, ROSS J. DAMIANI, JOHANN NEVELING, and
ADAM M. YATES, pages 715?719.

More about these later.

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-405-0796