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Re: Prognathodon (Mosasauridae) had shark-like hypocercal tail fin
It's interesting that several reptile lineages with shark-like tails
(ichthyosaurs, mosasaurs, ocean
crocs) all seemed to have kinked the caudal bones downward to reinforce the
lower lobe of the fin,
whereas sharks with asymmetrical tail lobes seem to all continue the caudals
into the upper lobe.
Was this just coincidence (an evolutionary toss of the coin), or could it have
something to do with
different buoyancy issues (lungs verses liver)? Does an asymmetrical tail
subtly change the pitch of
the animal while it swims, with a dominant upper lobe compensating in one
direction and a
dominant lower lobe compensating in another?
On Wed, Sep 11th, 2013 at 1:27 AM, Ben Creisler <email@example.com> wrote:
> From: Ben Creisler
> A new paper in Nature Communications:
> Johan Lindgren, Hani F. Kaddumi & Michael J. Polcyn (2013)
> Soft tissue preservation in a fossil marine lizard with a bilobed tail fin.
> Nature Communications 4, Article number: 2423
Spatial Data Analyst Australian Dinosaurs
Melbourne, Australia http://home.alphalink.com.au/~dannj