Galapagos ‘finch’ skulls get the tilt treatment

A few days ago, I matched a photo of a blue jay (Cyanocitta) to a skull and discovered the skull tipped back more than one would have thought it would beneath all those feathers.

Along the same lines
a paper by Zusi 1993 showed a series of Galapagos finches (now considered tanagers, evidently) that ignored that tilt according to photo overlays of in vivo specimens (Fig. 1). Zusi preferred to have all the jugals horizontal when they should descend based on in vivo photos.

Figure 1. GIF movie of Galapagos finch skulls, rotated to match photos.

Figure 1. GIF movie of Galapagos finch skulls, rotated to match photos.

 

Many birds,
like storks and shoebills, do tilt the skulls down anteriorly, like dogs and ornithocheirids do. Some don’t. It’s best to get it right.

Not sure if this affects scores
in analysis. But if the jugal ‘descends’ or the quadrate ‘leans,’ some scores may change.

References
Zusi RL 1993. Patterns of Diversity in the Avian Skull.  Fig. 8.9, pp. 391–437 in Hanken J and Hall BK, The skull, Volume 2: Patterns of structural and systematic diversity. University of Chicago Press, Chicago and London.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.