Re: tiny theropod on a tree trunk question

[Patrick Norton <ptnorton@suscom-maine.net>]

Jaime Headden wrote:

>  Balance issues? Woodpeckers and squirrels (the latter more than the 
> former,
> actually) are the only animals I know of, aside from arthropods, that 
> typically
> crawl around head-down on vertical clines.

(snip)

> birds that do "trunk-climbing" use a zygodactylous pes and
> their tail to form a "third leg". Parrots use their beaks instead of the 
> tail.

All the Piciforms (not just woodpeckers) have the first and fourth toes 
reversed, although not all are trunk climbers (Toucans, for example).  At 
the same time, Nuthatches and Creepers are trunk climbers, but don't have 
the zygodactylous foot found in woodpeckers.

PTN