Paleocene Dinosaurs?

I posted the message below to the Dinosaur Mailing List a couple of weeks ago. Like everyone else, I have long assumed this was just speculation and dismissed Fassett's evidence as probably Cretaceous bones being reworked into Paleocene deposits. Now I'm taking a harder look, and it is possible he might be onto something. Dare we hope that it might be true? Is it worth the possible disappointment if it turns out to be untrue? I think it is, because if it is true, it is going to be a HUGE story for paleontology.

I forgot to mention that Jim Fassett's latest published article on these purported Paleocene dinosaurs is in the book Dinosaurs of New Mexico (Lucas and Eckert, 2000).

It would be a fabulous discovery. I have felt for a long time that such a thing was possible. And even if this particular specimen does not pan out, I think that eventually we will find post-Cretaceous dinosaurs. They obviously must have been few and far between after the impact, but it's hard not to believe that some dinosaurs survived for a few millenia at least.

John M.

Few and far between? I see them every day! If only I could get them to stop defecating on my car....

Shhhh . . . don't let Cal hear you, or you'll be in hot water !

: would the newly diversifying mammals be able to pull this off?

Fewer small dinos existed as the Cretaceous wore on. Mammals need only be around armadillo size to impact dino reproduction (due to small dino eggs and babies). Mammals burrow. Mammals were likely able to see at night, dinos not.

Do you have some stats to back this up?

The only living 'dinosaurs' are those who still believe that birds are not only descended from dinosaurs, but also that birds are themselves dinosaurs. The end of the 'dinosaurs's' reign is getting closer and closer.

I'm not convinced that there were fewer small dinosaurs towards the end of the Cretaceous, but in any case it is irrelevant to my question. There were certainly plenty of small dinosaurs in the Jurassic and early Cretaceous and they didn't wipe out the the larger dinosaurs of their time through egg predation either.

And what evidence do you have that dinosaurs were never nocturnal? That would mean there were *no* sizable nocturnal animals

If mammals burrow and forage at night, and small dinos could do neither of these things, then these would be reasons enough. Chances are that large dinos had more to fear from other large dinosaurs

Janis and Damuth in Chpt 13 of Evolutionary Trends (ed. KJ McNamara) say: (By the Late Cretaceous), mammals apparently took over as the dominant small tetrapods, replacing...small dinosaurs.' They don't site stats. 65 mya representatives of theropods, ornithopods, ceratopsians, and ankylosaurs were the largest known for their entire lineages. This may not represent a mean increase in size