Re: Why did small dinos become extinct?

[David Marjanovic <david.marjanovic@gmx.at>]

> Can anyone supply references to peer-reviewed articles that discusss the 
> possibility that small non-flying predatory dinos were squeezed out by 
> lizards & snakes and / or birds and / or mammals and / or juveniles of 
> larger dino predators?

Except for the latter possibility, I don't think any such papers exist.

> On the other hands there's meagre but apparently growing evidence of
> small Maastrichtian non-flying theropods. Tim Williams says
> Richardoestesia was a small Maastrichtian non-flying theropod.

Was it smaller than *Dromaeosaurus*, the smallest flightless dinosaur in the 
Hell Creek Fm (1.8 m long)?

> http://www.dinodata.org/index.php?option=com_content&task=view&id=689&Itemid=25
> reports diverse small theropods and no large ones from the Hateg Basin
> (latest Maastrichtian, Roumania).

Most or all of those were AFAIK at least 1.8 m long, too.

> The bottom line at present appears to be that there's evidence of small
> Maastrichtian non-flying theropods but it's hard to pin down when they
> became extinct because at present the Hell Creek formation is the only
> terrestrial fossil bed that includes the K-T boundary.

There is one in India, too, but it's less well researched and apparently 
less fossil-rich...

> Does this mean I have to conclude that at present we don't have enough
> info to say much about how and when small non-flying predatory dinos
> became extinct?

Yes and no. We can still apply the principle of parsimony to conclude that 
they -- the 1.8-m-long and longer ones -- most likely died out in the mass 
extinction; especially considering the fact that all their likely prey 
suffered heavily in the mass extinction, too.

> If anyone has said this in a peer-reviewed publication,
> could someone please provide a reference.

It's unlikely anyone has said anything specifically on small flightless 
predatory dinosaurs.