Middle Jurassic birds: evidence from Morocco

[Jocelyn Falconnet <j.falconnet@gmail.com>]

Belvedere, M., G. Dyke, M. Hadri, et S. Ishigaki. The oldest evidence 
for birds in Northern Gondwana? Small tridactyl footprints from the 
Middle Jurassic of Msemrir (Morocco). Gondwana Research (In press).

We revise a famous set of fossil footprints that were described in the 
mid-1980s from the Middle Jurassic (Bathonian) of Morocco and that have 
often been considered to be an early record for Mesozoic birds. If 
correct, these tracks are the oldest records of birds from Gondwana and 
would have critical biogeographic and palaeobiological implications. The 
oldest skeletal fossils of avians are from the Late Jurassic of Germany 
(Laurasia). Thus, these important historical footprints are re-described 
and re-examined and new analyses are carried out on the additional 
tracks that also occur on the surface but that have never been described 
before. All the tracks on the surface show the same morphological 
characteristics, though their size is variable, and are compared here to 
known dinosaur and bird ichnotaxa. We used a laser scanner to generate a 
3D digital model of the slab; this new approach allowed detailed 
descriptions of the specimens, the identification of new footprints on 
the surface, and the conclusion that they were likely left by non-avian 
dinosaurs (rather than birds). We show the potential of this new 
approach to the study of fossil footprints and trackways; 
high-resolution imaging and laser scanning add new information 
fundamental for a revision of the criteria for distinguishing between 
closely-related vertebrate groups, in this case dinosaurs and birds.
http://www.sciencedirect.com/science/article/B7XNB-511GVMY-1/2/beadd073c68867688234b813deb12afe