Re: More on Digit Loss in Theropods

[NJPharris@aol.com]

In a message dated 10/22/01 3:00:37 PM Eastern Daylight Time, 
david.marjanovic@gmx.at writes:

> The praehalluces of frogs might be such a case -- if so, the only one known,
>  and maybe even a real reversal that appeared while the necessary genes were
>  still present (I'm speculating). (These toes are very short, so I can't see
>  an advantage in their presence; however, they are not duplicates of the
>  halluces and have separate tiny metatarsals.) Seems like it is very hard
>  IMHO.

My memory is that the prepollex and prehallux are retentions of the digits 
derived from the line of development that passes through the radius (all 
digits in most tetrapods are derived from a line of development passing 
through the ulna), which are resorbed early in other tetrapods.

--Nick P.