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Plesiosaur remains from Arctic Melville Island, Nunavut, Canada
From: Ben Creisler
A new paper:
Matthew J. Vavrek, Benjamin C. Wilhelm, Erin E. Maxwell & Hans C.E.
Arctic plesiosaurs from the Lower Cretaceous of Melville Island,
Cretaceous Research 50: 273–281
Disarticulated remains of juvenile polycotylid plesiosaurs.
Fossils from Melville Island in the High Arctic of Canada.
Earliest record of polycotylid plesiosaurs in North America.
Occurrence in Arctic predates formation of Western Interior Seaway.
High proportion of juveniles in freshwater sediments.
An expedition to Melville Island in Nunavut, Canada, recovered the
fragmentary fossils of several plesiosaurs from non-marine deposits of
the Hauterivian–Aptian Isachsen Formation. These plesiosaur fossils
are some of the oldest Early Cretaceous records of the group in North
America, and they likely predate the formation of a continuous Western
Interior Seaway. The plesiosaurs from Melville Island appear to be
primarily juveniles, and would have been living in a region that
experienced at least seasonally cool temperatures. The presence of
these fossils in a fluvial deposit support previous suggestions that
juvenile plesiosaurs may have preferentially inhabited shallower
waters rather than open marine environments. These fossils also show
that polycotylid plesiosaurs were able to rapidly disperse and
colonize high latitude coastal regions, as their occurrence in Arctic
Canada only slightly postdates the first confirmed appearance of the
group in Australia.