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Re: Dino heart--Williston's prediction comes true!
With respect to the "primitive" crocodilian heart, I saw a show on
Discovery channel or animal channel recently in which it is claimed that
the crocodilian heart is the most sophisticated one in existence. Rather
than having unoxygenated blood just sloshing into the oxygenated blood
stream, the heart allows blood to circulate in a closed loop to the
brain while shutting down blood flow to extremities, allowing a longer
time for the animal to stay underwater. This is an adaptation to an
"underwater lie-in-wait" predatory strategy.
Does anyone know if this is correct? If so, crocodilian hearts may
be specialized to their lifestyle and not represent a primitive
condition prior to the split of dinosaurs from crocs.