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Late Cretaceous dinosaurs from James Ross Basin, West Antarctica



From: Ben Creisler
bcreisler@gmail.com


A new online paper not yet mentioned:

Marcelo A. Reguero, Claudia P. Tambussi, Rodolfo A. Coria and Sergio
A. Marenssi  (2013)
Late Cretaceous dinosaurs from the James Ross Basin, West Antarctica.
Antarctic Palaeoenvironments and Earth-Surface Processes : Geological
Society, London, Special Publications 381 (advance online publication)
doi: 10.1144/SP381.20
http://sp.lyellcollection.org/content/early/2013/07/24/SP381.20.abstract?sid=79f381c5-3955-43fd-b01b-ec7bd8f1e141

The fossil record of terrestrial vertebrates from the Late Cretaceous
of Antarctica is currently composed of non-avian and avian dinosaurs
from the marine sediments of the James Ross Basin, Antarctic Peninsula
(West Antarctica). Although two dinosaurian formational assemblages
(Late Campanian/Early Maastrichtian and Late Maastrichtian) are known,
the record is still scattered, and evolutionary scenarios are
tentative. Ten non-avian dinosaurs have been reported from Coniacian
to Maastrichtian deposits, along with possible sauropod footprints of
Early Maastrichtian age from Snow Hill Island. Five avian dinosaurs
have been recorded or described exclusively from the Maastrichtian.
The presence of an advanced titanosaur with characteristic procoelous
mid-caudal vertebrae in Snow Hill Island Formation at Santa Marta Cove
implies that the group achieved a global distribution by the Late
Campanian. The Late Campanian/Early Maastrichtian non-avian dinosaur
(ankylosaurs, ornithopods and dromaeosaurid theropods) clades probably
attained a near-cosmopolitan distribution before the Late Cretaceous,
and some aspects of this hallmark ‘Gondwanan’ fauna may therefore
reflect climate-driven provinciality, not vicariant evolution driven
by continental fragmentation. Antarctic Late Cretaceous avian
dinosaurs are rare. They are restricted to the Maastrichtian and
consist of a cariamid?, gaviids, a charadriiform and the basal
Anseriformes Vegavis, and provide the first strong evidence for a
basal radiation of birds known to exist in the Cretaceous.