Named By: Louis Agassiz - 1849.
Classification: Chordata, Reptilia, Testudines, Cryptodira, Protostegidae.
Species: A. mortoni (type).
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).
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
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
especially adapted for cutting bone and shell like those of
were all swimming in the oceans at the same time as
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.
-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.