re: hybodonts at K/T correction

[Tom Holtz <tholtz@geochange.er.usgs.gov>]

>Sorry, sent last message when I meant to abort.
>On hybodonts at the K/T boundary: their range virtually but not absolutely
>ends at the Maastrichtian (not as I posted Campanian) with loss of the
>common genus Lissodus.  But, they persisted until the Paleocene: thus,
>the K/T event had effectively no influence on them.  A point to consider
>(a declining group unaffected by the apparent chaos).

And to add to this: the champsosaurs, a bunch of small, superficially
crocodile-like archosauromorphs (or at least they were archosauromorphs the
last time I checked ;-)) which had been around since the Jurassic, had
become more abundant in the Cretaceous, and sailed through the extinction
event.  These guys died out sometime in the Paleogene.

                                
Thomas R. Holtz, Jr.                                   
tholtz@geochange.er.usgs.gov
Vertebrate Paleontologist in Exile                  Phone:      703-648-5280
U.S. Geological Survey                                FAX:      703-648-5420
Branch of Paleontology & Stratigraphy
MS 970 National Center
Reston, VA  22092
U.S.A.