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Pterodaustro



Martin wrote:

"On a slightly different topic, the so-called Flamingo pterodactly"

That would be the pterodactyloid *Pterdaustro guinazui* (Lower Cret.,
Argentina)...

"(Oh how I
wish British Airways had not lost my luggage with my newly-purchased
dino books in it!) seems always to be illustrated standing statically in
shallow water, filtering the water for crustacea using the _front part of
it's
upcurved bristly snout. This seems incorrect to me, because the bristles
actually extend virtually the whole length of the snout, with scarcely any
change in their length. To me this indicates the whole length of the snout
was
intended to be used as a filter, and the only way I can see to do this is by
laying the snout along the surface of the water and sweeping from side to
side
(perhpas advancing one pace for each sweep) , scooping up whatever floats on
the surface (duckweedy find of plants, perhaps?). What do you think? Does
anyone know if the articulations of the neck show any adaptations for
sideways
sweeping?"

My up-close experience with pterosaurs is pretty much limited to the
pteranodontids, in which, to quote Wellnhofer (1991), "additional [cervical]
processes, so-called exapophyses, have formed , jutting out ventrally at both
ends of the vertebra. This five-point joint in the cervical vertebrae
prevented cervical torsion and major sideways movement." I've always
interpreted this as an adaptation to aid in the support of the rather large
heads of animals like *Pteranodon* and *Quetzalcoatlus.*

I know that the cervicals of *Pterdaustro* are rather elongated, but am
unaware of anything that would have prevented a lateral sweeping motion.

I'm pretty sure that Sibbick's restoration in Wellnhofer's book
(THE ILLUSTRATED ENCYCLOPEDIA OF PREHISTORIC FLYING REPTILES) is meant to
indicate that the entire length of the mandible *is* being used in seiving.
Also, remember that straining occurs not only while the pterosaur's jaws are
submerged, but after the head is lifted, as the water flows back out through
the bristles.

Caitlin R. Kiernan