nocturnal Archaeopteryx

["Richard W. Travsky" <rtravsky@uwyo.edu>]

darn interesting

http://www.newscientist.com/article/mg20627545.500-archaeopteryx-may-have-hunted-at-night.html

LIKE a modern owl, Archaeopteryx may have come alive at night. The shapes 
of eye sockets differ predictably in birds that feed during the day, night 
or twilight, according to a study that promises to spill the beans on the 
dino-bird's lifestyle.

When Lars Schmitz at the University of California, Davis, studied 77 bird 
species, he found he could predict the foraging lifestyle of any species 
simply by measuring the bones that their eyes are set in. Each bird pupil 
is surrounded by a ring of bony segments called the scleral ring. Schmitz 
found that the outer and inner diameter of this ring, combined with the 
depth of eye sockets, could closely predict when a bird forages (Vision 
Research, DOI: 10.1016/j.visres.2010.03.009). This opens up the 
tantalising possibility of discovering whether extinct birds were 
nocturnal.

Schmitz is currently making detailed measurements, but a quick look at 
Archaeopteryx fossils reveals that it had wide scleral rings and deep eye 
sockets, says Derek Yalden at the University of Manchester. According to 
Schmitz's findings, this would make the dino-bird nocturnal.

"I don't think it had occurred to anyone to suggest this," says Yalden. If 
he is right, all drawings of Archaeopteryx flying through the daytime 
skies of early Earth will need to be revisited.