SUCKING WALRUSES

[darren.naish@port.ac.uk]

Nick L wrote...

>  Both sea otters and walruses have massive crushing teeth to 
> deal with molluscs

Walruses do not use their teeth to crush prey, as was once thought - 
they are suction feeders that cruise head-down along the seabed and 
suck off the protruding soft parts of bivalves. Wear on the teeth is 
apparently generated by sand grains which are sucked in with the prey. 
This foraging method explains the characteristic wear on walrus tusks 
(the leading edge of the distal end is always polished smooth) and also 
the strongly vaulted palate and phenomenal throat musculture. A 
sucking walrus can generate 1 negative atmosphere and specimens in 
captivity have removed the heavy metal plugs from the bottoms of 
their swimming pools.

For references see King's _Seals of the World_ and also de Muizon's 
work on _Odobenocetops_, a walrus-mimicking odontocete whale.


"Cambridge University Press should be 
ashamed of abandoning academic standards 
and should be worried about whether competent
scientists will now publish with them."

 -- P. R. Ehrlich (2002) reviewing Lomborg's 
_The Skeptical Environmentalist: Measuring the State of the World_

DARREN NAISH 
PALAEOBIOLOGY RESEARCH GROUP
School of Earth & Environmental Sciences
UNIVERSITY OF PORTSMOUTH
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