From Wikipedia, the free encyclopedia
Extinct genus of turtles
Itilochelys
is an extinct
genus
of
sea turtle
in the family
Cheloniidae
containing the
single
species
Itilochelys rasstrigin
. The species is known only from the Early Paleocene,
Danian stage
Rasstrigin
2 locality,
Dubovsky District
,
Volgograd Oblast
,
Russia
.
[1]
History and classification
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Itilochelys rasstrigin
is known only from three fossils, the
holotype
, specimen number "ZIN PH 1/118" and two referred specimens, numbers "ZIN PH 2/118" and "ZIN PH 3/118" . The type specimen is composed of a grouping of cervical vertebrae I-III, partial skull, and disarticulated lower jaw. Specimen ZIN PH 2/118 is an isolated section of
dentary
while ZIN PH 3/118 is a right
humerus
. The fossils were all recovered by A. A. Yarkov from fossiliferous outcrops of the Beryozovaya beds exposed at the Rasstrigin 2 locality.
[1]
As of 2011, the type and referred specimens are preserved in the
Paleoherptological
collections housed at the
Zoological Institute of the Russian Academy of Sciences
, in
Saint Petersburg
, Russia.
Itilochelys
was first studied by I. G. Danilov and A. O. Averianov of the Zoological Institute along with A. A. Yarkov of the Natural History, Humanitarian Institute in Volgograd. Their 2010
type description
of the genus and species was published in the journal
Proceedings of the Zoological Institute RSA
.
[1]
The
generic
name was coined by Danilov, Averianov, and Yarkov as a combination of the medieval Arabian/Persian name of the
Volga River
,
Itil
, along with the
Greek
"chelys", meaning turtle. The
specific epithet
rasstrigin
is in reference to the type locality of the specimen.
[1]
Itilochelys rasstrigin
is one of three fossil cheloniid sea turtle taxa which have been recovered from the Volgograd region and the most complete specimen recovered so far. The other two taxa are represented by a specimen of the genus
Euclastes
known from the Karpovka site and a specimen related to the genus
Tasbacka
from the Malaya Ivanovka site.
[1]
The placement of
Itilochelys rasstrigin
in the family Cheloniidae is supported by the contact of the squamosal and parietal bones, an emarginated v-shaped crest on the underside of the basisphenoid, and features of the nasal bone structure. Placement of the species as a
stem member
in the family is based on the structure of the humerus which shows a morphology transitioning towards the derived pelagic structuring of modern cheloniids.
[1]
References
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