Body Size Evolution in Mesozoic Birds

[David Peters <davidrpeters@earthlink.net>]

GL wrote:

J Evol Biol. 2008 Jan 9 [Epub ahead of print]
Body size evolution in Mesozoic birds.Hone DW, Dyke GJ, Haden M,  
Benton MJ.
Bayerische Staatssammlung für Paläontologie und Geologie,
Richard-Wagner-Straße, München, Germany.

If the authors used another straight line, as they did between data  
point: _Anurognathus_ and data point: _Quetzalcoatlus_ in pterosaurs,  
then any size increase above that of _Archaeopteryx_ would indicate  
Cope's Rule.

I'm still a fan of lines that look more like roller coaster tracks  
through time. More data point hits. Clearer picture.

Cope's Rule, because it starts small succeeding evolutionary novelty,  
(arbitrarily?) excludes the larger ancestral taxa to whatever the  
subject taxon is. Tell me if I'm wrong, but aren't basal taxa of many  
large branches tiny?

Reptilia (Amniota)
Dinosauria
Pterosauria
Mammalia
Aves

Perhaps there could be another rule of decreasing size preceding  
evolutionary novelty.

David Peters
St. Louis