Rostral structure in Thalattosauria (Reptilia, Diapsida)

Publication Status is "Submitted" Or "In Press: 
LDEO Publication: 
Publication Type: 
Year of Publication: 
2005
Editor: 
Journal Title: 
Canadian Journal of Earth Sciences
Journal Date: 
Dec
Place Published: 
Tertiary Title: 
Volume: 
42
Issue: 
12
Pages: 
2081-2086
Section / Start page: 
Publisher: 
ISBN Number: 
0008-4077
ISSN Number: 
Edition: 
Short Title: 
Accession Number: 
ISI:000237356900002
LDEO Publication Number: 
Call Number: 
Abstract: 

The rostral structure of thalattosaurs is reviewed oil the basis of a re-investigation of the holotype of Nectosaurus halius and Thalattosaurus alexandrae. The askeptosaurid genera Askeptosaurus and Anshunsaurus share all elongated, parallel-sided rostrum that terminates in a blunt tip. A diastema separating the premaxillary from the maxillary teeth is absent. The claraziid genera Clarazia and Thalattosaurus share a relatively shorter rostrum that has convergent lateral margins and that terminates in a pointed tip. A diastema separating the premaxillary from the maxillary teeth is present. The well-preserved holotype of Nectosaurus halius shows a highly derived rostral structure. The maxilla is short with an anteriorly truncated (vertical) margin, a narrow but high ascending process, and a dorsally curving medial flange that is in natural articulation with the ventrally deflected vomer. These findings corroborate Peyer's original reconstruction of Hescheleria with a nearly vertically placed premaxilla.

Notes: 

040CPTimes Cited:2Cited References Count:24

DOI: 
Doi 10.1139/E05-076