San Diego Natural History Museum    Mesocyon coryphaeus Short-
faced dog Family: Canidae  Oligocene Epoch The ancestry of dog-
like carnivores, as well as cat-like carnivores, goes back to
the miacids, a group of carnivorans from some 45 mya, which
shared certain features of both cats and dogs. For example,
miacids, such as Tapocyon, had retractable claws like a cat, but
had broad back molar teeth like a dog. These two groups diverged
about 40 mya, with the ancestors of dogs, bears, weasels,
raccoons, and seals going off in one evolutionary direction,
while the ancestors of cats, hyenas, and civets diverged in
another direction.  Mesocyon coryphaeus has been collected from
central Oregon in the John Day Formation, and in California.  In
Our Region These fossils were found at EastLake and Otay Ranch,
in Chula Vista, California.  Mesocyon fossil. Mesocyon
coryphaeus SDSNH specimen no. 3280/28210  Mesocyon fossil.
Close-up: Mesocyon coryphaeus SDSNH specimen no. 3280/28210
Mesocyon was a short-faced canid, about