Crocs and the K-T

[KELL00BELL@aol.com]

    Stomatosuchus was an unusual giant crocodile from the Cretaceous of North
Africa.  Some of its features suggest it ambushed dinosaurs coming to the
water's edge.  In addition to being a huge (15m) freshwater croc,
Stomatosuchus had a wide, flat skull with upwardly directed eyes.  A flat
skull could have aided concealment in the shallow water near a riverbank or
lake shore, while the high eyes, acting as periscopes, kept watch for
approaching prey.  But how could Stomatosuchus kill dinosaurs with the small
teeth of its upper jaw, and its weakly constructed, toothless lower jaw?
Perhaps it bolted down baby titanosaurs whole.  No crocodile, no matter how
well-armed, could overcome massive adult titanosaurs, but there were many
small ones after the nesting season.  The African climate was no less
sweltering then, and titanosaurs, like modern mammals, frequently drank or
immersed in water to cool off.  Stomatosuchus had many opportunities to
select victims of small size.  In America, Deinosuchus evolved the means to
kill ornithiscians, which were small enough to be beatable, even when adult.
    Of course, dependence on dinosaurian prey guaranteed extinction at the
K-T, regardless of its cause.  The survival of fish-eating dyrosaurs and many
other crocodilians argues that stomatosuchids and deinosuchids were not
directly affected by the cause of dinosaur extinction, but by the latter
alone.
    Crocodilian survival should, however, limit the factors responsible for
the K-T, specifically ruling out an impact winter.  No crocodilian was likely
to have survived the severe plunge in temperatures resulting from the
hypothesized loss of sunlight for months or years.  Even alligators, which
hibernate, are confined to mild, southerly areas.  The persistence of such
thermophilic organisms should refute the impact scenario.  Marine life may
have succumbed to cooler temperatures, but crocodilians had an advantage, the
ability to bask.  That would explain their survival, provided there was no
interruption of sunlight.
    Kelly Bell