Allosaurus variation

[bh480@scn.org]

From: Ben Creisler
bh480@scn.org

In case this paper has not been mentioned yet:

Kenneth Carpenter (2010)
Variation in a Population of Theropoda (Dinosauria): 
Allosaurus from the Cleveland-Lloyd Quarry (Upper 
Jurassic), Utah, USA
Paleontological Research 14(4):250-259 (2010) 
doi: 10.2517/1342-8144-14.4.250
http://www.bioone.org/doi/abs/10.2517/1342-8144-14.4.250


Ontogenetic and individual variation in a population of 
the large theropod Allosaurus cf. A. fragilis was 
examined using the Björk superimposition method on the 
premaxillae, maxillae, lachrymal, postorbital, and jugal. 
This method allows utilization of incomplete specimens 
without having to estimate (fabricate) missing data. In 
addition, it visually shows regions of ontogenetic change 
and variation. Comparison of these results with other 
morphometric studies of the same specimens show that most 
allometric trends are not supported. Instead, ontogenetic 
change is mostly isometric. In addition, the wide range 
of individual variation in all the skull elements 
analyzed makes some autapomorphic characters used to 
define other theropod taxa suspect.