RE: Nemicolopterus

[Tim Williams <twilliams_alpha@hotmail.com>]

Dann Pigdon wrote:

>> Here's the article abstract:> 
>> http://www.pnas.org/cgi/content/abstract/0707728105v1 
>
>
> Here's the New Scientist article (with an amazing 
> picture):http://www.newscientist.com/article/dn13298-tiny-perching-
> pterosaur-discover ed.html  


Yep, the picture is amazing.

However, the idea that _Nemicolopterus_ was either (a) a percher, or (b) an 
insect-eater is not exactly compelling.  As the authors state, the features 
which strongly indicate that _Nemicolopterus_ was arboreal are: strongly curved 
penultimate phalanges of the foot (especially first and fourth toes); and 
penultimate phalanx of the fourth digit longer than the first.  Overall, this 
indicates suspensory behavior (antipronogrady), which is not perching.  There 
is no reversed hallux, for example.

As for insectivory, the skull of _Nemicolopterus_ is long and slender, not 
broad and wide (as in anurognathids).  Anurognathids have been interpreted as 
aerial insectivores (i.e., catching flying insects on the wing) - like the 
modern frogmouth (which is essentially what "Anurognathus" means).  Until the 
discovery of _Nemicolopterus_, anurognathids were considered the most arboreal 
pterosaurs.

Also, the phylogeny of Wang et al. recovers anurognathids at the base of the 
Pterosauria.  This is interesting because it positions a clade of putative 
arboreal insectivores closest to the base of Pterosauria.  I hate the old 
"trees-down" vs "ground-up" dichotomy for the origin of pterosaur flight as 
much as I hate it for the origin of avian flight.  But if this topology holds 
up, it may lend support for an arboreal ("trees-down") contribution to early 
pterosaur evolution.

Cheers

Tim
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