Jan.
16, 2013 — Palaeontologists who examined a new fossil found in southern
California have thrown doubt on earlier claims that a "killer walrus"
once existed.
A
University of Otago geology PhD student Robert Boessenecker and co-author
Morgan Churchill from the University of Wyoming have just published their paper
about the fossil in the online scientific journal PLOS One.
The
paper reports that the new fossil-find, of the extinct
walrus Pelagiarctos from southern California, prompts a different
hypothesis to an earlier one that a "killer walrus" existed, preying
on other marine mammals and/or birds.
Fossils
of the walrus were originally found in the 1980s. The large, robust size of the
jaw bone, along with the sharp pointed cusps of the teeth similar to modern
bone-cracking carnivores like hyenas, suggested that Pelagiarctos fed
upon other marine mammals rather than the typical diet of fish as in modern
walruses.
However
the new fossil, a lower jaw with teeth, and more complete than the original
fossil, suggests to the Otago and Wyoming palaeontologists that
the Pelagiarctos was more of a fish eater as it lacked adaptations for
being a "killer walrus."
The
evidence pointed to the tooth shape being unlikely to have been adapted for
feeding upon large prey; instead it was an example of primitively retained
tooth shape.
"This
new find indicates that this enigmatic walrus would have appeared similar in
life to modern sea lions, with a deep snout and large canines," says Mr
Boessenecker.
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Modern walrus have been known to kill and eat other mammals,including humans.
ReplyDeleteModern walrus have been known to kill and eat other mammals,including humans.
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