Name:
Atlantochelys
(Atlantic shell).
Phonetic: At-lan-to-chel-iss.
Named By: Louis Agassiz - 1849.
Classification: Chordata, Reptilia, Testudines,
Cryptodira, Protostegidae.
Species: A. mortoni (type).
Diet: Carnivore.
Size: Comparison to related genera of turtles points
to an estimated length of about 3 meters.
Known locations: USA, New Jersey.
Time period: Campanian of the Cretaceous.
Fossil representation: Humerus (upper arm bone).
Atlantochelys
was first named in 1849 and based upon the description of half a
humerus (analogous to your upper arm bone). For well over one
hundred and fifty years that was it, but then in 2012 the missing
half of this bone was actually matched up to the original specimen.
Although Atlantochelys may be considered dubious
because of still a
lack of overall fossil remains, the humerus of Atlantochelys
is still
identified as coming from a protostegid turtle, while at the same
time not like other known specimens. Scaling the size of the humerus
to relative genera has yielded an approximate estimate that
Atlantochelys grew to about three meters in length.
This large size
would have been the best protection for Atlantochelys
given that large
marine reptiles called mosasaurs
as well as large sharks
with teeth
especially adapted for cutting bone and shell like those of
Cretoxyrhina
were all swimming in the oceans at the same time as
Atlantochelys.
Atlantochelys
has been classed within the Protostegidae group of turtles, and so
speculated reconstructions of Atlantochelys are
usually based upon
other members of this group such as Protostega
and Archelon,
both of
which seem to have been larger than Atlantochelys.
Further reading
- Remarks on crocodiles of the green sand of New Jersey and on
Atlantochelys. - Proceedings of the National Academy
of Sciences
4:169-169. - L. Agassiz - 1849.
-Two halves make a holotype: two hundred years between discoveries.
- Proceedings of the Academy of Natural Sciences of Philadelphia
163. - David C. Parris, Jason P. Schein, Edward B.
Daeschler, Edward S. Gilmore, Jason C. Poole &
Rodrigo & A. Pellegrini - 2014.
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