new paper on Ardley trackway site, Oxfordshire, UK

[Jose Ignacio Ruiz-Omeñaca <jigruiz@unizar.es>]

Sorry if this has been posted:

A MIDDLE JURASSIC DINOSAUR TRACKWAY SITE FROM OXFORDSHIRE, UK

by JULIA J. DAY, DAVID B. NORMAN, ANDREW S. GALE, PAUL UPCHURCH and H. PHILIP 
POWELL

Palaeontology, Vol. 47, Part 2, 2004, pp. 319-348

ABSTRACT. The Middle Jurassic (Bathonian) Ardley trackway site in Oxfordshire, 
UK is described in detail. The track site is extensive, containing over 40 
more-or-less continuous theropod and sauropod trackways preserved together on a 
single bedding plane with some trackways up to 180m in length. The trackways 
display reasonable preservation, with claw marks discernible. Sauropod 
trackways are by far the most abundant and are representative of taxa that 
exhibit both narrow and wide-gauge styles of locomotion. Theropod trackways are 
represented by large tridactyl prints and claw impressions that display 
exceptionally low pace angulation values during their walking phase. One 
theropod trackway is unique in that it reveals a gait transition associated 
with a temporary increase of speed. These dinosaurs were walking over a 
lime-mud firmground to hardground that was emergent, or locally very shallowly 
submerged. GPS (Global Positioning Satellite) data reveal that the tracks, 
prese!
 rv!
ed during a short time interval, trend in a northeasterly direction. 
Multi-herding behaviour is suggested for the sauropods of differing size. The 
discovery of this site adds significantly to our knowledge of the taxonomic 
composition of Middle Jurassic ecosystems. Evidence concerning locomotor styles 
employed by saurischian dinosaurs, footprint identification, potential 
trackmaker, social interactions and observations concerning estimates of Middle 
Jurassic faunal diversity, as well as aspects of dinosaur locomotor evolution 
are discussed.

KEY WORDS: theropod, sauropod, Bathonian, Megalosaurus, Cetiosaurus, GPS, 
locomotion.

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Jose Ignacio Ruiz-Omeñaca
Departamento de Ciencias de la Tierra
Area de Paleontologia
Universidad de Zaragoza
E-50009 ZARAGOZA, SPAIN

tel: (+34) 976 761000 ext. 3160
fax: (+34) 976 761106
e-mail: jigruiz@unizar.es
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