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Wilson new Sauropods phylogeny



DearList Members for all the Sauropods fun in the latest issue of
"Zoological Journal of the Linnean Society there's the new Wilson's
Sauropods phylogeny:
Complete refs:
_Wilson J.A. 2002 Sauropod dinosaur phylogeny: critique and cladistic
analysis Zoological Journal of the Linnean Society Vol. 136 Issue 2 pp:
215-277.

Follows the abstract:
Sauropoda is among the most diverse and widespread Dinosaur lineages, having
attained a global distribution by the Middle Jurassic that was built on
throughout the Cretaceous. These gigantic herbivores are characterized by
numerous skeletal specializations that accrued over a 140 million year. This
fascinating evolutionary history has fuelled interest for more than a
century, yet aspects of Sauropod interrelationships remain unresolved.
In this paper, Wilson presents a lower-level phylogenetic analysis of
Sauropoda in two parts. First, the two most comprehensive analyses of
Sauropoda are critiqued to identify points of agreement and difference and
to create a core of character data for subsequent analyses. Second, a
generic-level phylogenetic analysis of 234 characters in 27 sauropod taxa is
presented that identifies well supported nodes as well as areas of poor
resolution. The analysis resolves six Sauropod outgroups to
Neosauropoda,which comprises the large-nostrilled clade Macronaria and the
peg-toothed clade Diplodocoidea. Diplodocoidea includes Rebbachisauridae,
Dicraeosauridae,and Diplodocidae, whose monophyly and interrelationships are
supported largely by cranial and vertebral synapomorphies. In contrast, the
arrangement of  Macronarians, particularly those of Titanosaurs,are based on
a preponderance of appendicular synapomorphies. The purported Chinese clade
'Euhelopodidae' is shown to comprise a polyphyletic lineage of basal
Sauropods and Neosauropods. The synapomorphies supporting this topology
allow more specific determination for the more than 50 fragmentary Sauropod
taxa not included in this analysis. Their distribution and phylogenetic
affinities underscore the diversity of  Titanosauria and the paucity of Late
Triassic and Early Jurassic genera. The diversification of Titanosauria
during the Cretaceous and origin of the Sauropod body plan during the Late
Triassic remain frontiers for future studies.

By
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Alessandro Marisa
Via Achille Grandi n°18
Rovereto (TN) ITALY
Tel: 039-0464-434658 Email: amaris@tin.it
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