Daniel Bensen <firstname.lastname@example.org> wrote:
Morgan Churchill:>>maybe Mosasaurs
invade freshwater enviroments, evolving into forms filling the niches of
todays crocodiles. Meanwhile, their marine
relative get even more serpentine and sea serpent like.<<
Sea serpent's, maybe, but I think crocodiles were doing a fine job of
being crocodiles, already. I can imagine mosasaurs evolving into seal
or dolphin-like forms, however, and whales, too.
their is a trend for mosasaurs getting more serpentine as time goes by, so it's hard for me to imagine them reversing direction and bulking up into whale like forms. I think it's more likely that the plesiosaurs however would develop whale and dolphin like forms, as some of the pliosaurs come quite close
Also, IIRC, Mike Everhart mentions on his website evidence that mosasaurs were were starting to invade freshwater habitats toward the end of the Cretaceous. While I don't see a total displacement of crocs, I think some rathing interesting freshwater species might evolve in the larger, stable freshwater environments
Andy Farke:>>Perhaps the small aquatic critters niche is
one that the mammals would have successfully exploited.<<
I don't know. I rather think mammals would still be suited for those
jobs. Maybe we'd have marsupial otters (such things exist in South
America, anyway) and multicuberculate beavers?
Or monotremes, they were already established in aquatic niches