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Re: Nocturnal dinosaurs in Science magazine

On Fri, Apr 15th, 2011 at 5:21 AM, "bh480@scn.org" <bh480@scn.org> wrote: 

> In the latest issue of Science magazine:
> Lars Schmitz and Ryosuke Motani (2011)
> Nocturnality in Dinosaurs Inferred from Scleral Ring and Orbit Morphology.
> Science Express Index 
> Science DOI: 10.1126/science.1200043 
> http://www.sciencemag.org/content/early/2011/04/13/science.1200043
> Abstract
> Variation in daily activity patterns facilitates temporal partitioning of
> habitat and resources among species. Knowledge of temporal niche
> partitioning in paleobiological systems has been limited by the difficulty
> of obtaining reliable information about activity patterns from fossils. On
> the basis of an analysis of scleral ring and orbit morphology in 33
> archosaurs, including dinosaurs and pterosaurs, we show that the eyes of
> Mesozoic archosaurs were adapted to all major types of diel activity (that
> is, nocturnal, diurnal, and cathemeral) and provide concrete evidence of
> temporal niche partitioning in the Mesozoic. Similar to extant amniotes,
> flyers were predominantly diurnal; terrestrial predators, at least
> partially, nocturnal; and large herbivores, cathemeral. These similarities
> suggest that ecology drives the evolution of diel activity patterns. 

Is crepuscular not a 'major' diel activity type? Although I wonder how you'd 
tell crepuscular from 
nocturnal or cathemeral based on scleral morphology alone.


Dann Pigdon
Spatial Data Analyst               Australian Dinosaurs
Melbourne, Australia               http://home.alphalink.com.au/~dannj