Tanystropheus

[Marco Auditore <maaudito@tin.it>]

Dear all,

I would notify that is out a new monograph on Tanystropheus:

Nosotti, Stefania, 2007, Tanystropheus longobardicus (Reptilia, 
Protorosauria): re-interpretations of the anatomy based on new specimens 
from the Middle Triassic of Besano (Lombardy, Northern Italy). Memorie 
della Società Italiana di Scienze Naturali e del Museo Civico di Storia 
Naturale di Milano, Vol. XXXV - Fascicolo III, pp. 1-88.

Abstract (long): After more than one century since the first report of 
Tanystropheus longobardicus from the middle triassic of Besano, new 
specimens from the same outcrops are described. These specimens include two 
articulated skeletons and an isolated pes, all from small-sized 
individuals, and fragmentary remains of larger individuals, i.e. a skull 
with some associated cervical vertebrae, an isolated dorsal vertebra and 
isolated cervical ribs.
This new material confirms the presence of T. longobardicus in the Besano 
Formation, which previously yielded few evidence. Moreover, it includes 
remarkably complete and well preserved specimens which provided the 
opportunity of a new interpretation of the anatomy of Tanystropheus, 
formerly described on the basis of a rich sample from the Swiss 
Grenzbitumenzone.
The description presented here applies to small-sized individuals of 
Tanystropheus, traditionally interpreted as the juveniles of T. 
longobardicus. However, the point is raised that they might represent the 
adults of a different species, demonstrating the presence of two taxa among 
the Swiss and Italian material referred to T. longobardicus. The holotype, 
and the single know specimens, of the small-sized Tanystropheus meridensis 
from the Meride Limestone is also considered and re-interpretated, leading 
to the conclusion that the species is probably a junior synonym of T. 
longobardicus.
Comparisions of the specimens of Tanystropheus from the Besano Formation 
with those from the equivalent Grenzbitumenzone helped to find the 
problematic elements of the classical reconstruction.
A new reconstruction of the skull of Tanystropheus is presented based on a 
three-dimensional clay model, with a re-interpretation of the pre-orbital 
region, the skull roof, and the lower jaw. The reconstruction of the 
temporal region of the skull is shown to be highly problematical. Finally, 
the new specimens confirm the presence of a sclerotic ring in Tanystropheus.
In the postcranial skeleton, the more important new information concern the 
morphology of the appendicular skeleton, which is remarkably well preserved 
in the new specimens. In particular, preservation of complete and perfectly 
articulated manus and pedes for the first time yield unequivocal evidence 
on their morphology.
The anatomy of the appendicular skeleton, in particular that of the 
hindlimb, is discussed in the context of locomotion mode. An overall view 
of previous studies on the mode of life of Tanystropheus is presented and 
discussed. According to these results, Tanystropheus should be regarded as 
a marine protorosaur, with close terrestrial ancestors, living in shallow 
waters. The feeding strategy of Tanystropheus is discussed, on the 
assumption that it likely was a slow, axial or paraxial swimmer with a 
stiff neck.
In conclusion, the new information obtained from the specimens described 
here is evaluated in the context of the recent cladistic analyses of 
protorosaurian relationships, highlighting the bearing of systematic 
anatomical work of the original materials on the description and coding of 
phylogenetically informative characters.

The volume can be ordered at the following address:

info@scienzenaturali.org

Marco

MARCO AUDITORE
Via S.Giovanni Battista, 7/23
16154 GENOVA SESTRI P. - ITALY
Tel: +39-010-6044259
E-mail: maaudito@tin.it
Web-Page: http://www.studiotsunami.it/minmi/index.htm

"Volunteer of Museo Paleontologico Cittadino, Monfalcone"
Museum Web-Page: http://www.museomonfalcone.it