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Re: New PLOS One paper on T rex infections

Is this infection also found in living alligators/crocs, or is it strictly an 
avian infection?


---------- Original Message ----------
From: Dan Chure <danchure@easilink.com>
To: DML <dinosaur@usc.edu>
Subject: New PLOS One paper on T rex infections
Date: Tue, 29 Sep 2009 18:27:03 -0600

New paper available at


Common Avian Infection Plagued the Tyrant Dinosaurs
Ewan D. S. Wolff1*, Steven W. Salisbury2,3*, John R. Horner4, David J. 

Tyrannosaurus rex and other tyrannosaurid fossils often display 
multiple, smooth-edged full-thickness erosive
lesions on the mandible, either unilaterally or bilaterally. The cause 
of these lesions in the Tyrannosaurus rex specimen FMNH
PR2081 (known informally by the name ‘Sue’) has previously been 
attributed to actinomycosis, a bacterial bone infection, or
bite wounds from other tyrannosaurids.

Methodology/Principal Findings: We conducted an extensive survey of 
tyrannosaurid specimens and identified ten
individuals with full-thickness erosive lesions. These lesions were 
described, measured and photographed for comparison
with one another. We also conducted an extensive survey of related 
archosaurs for similar lesions. We show here that these
lesions are consistent with those caused by an avian parasitic infection 
called trichomonosis, which causes similar
abnormalities on the mandible of modern birds, in particular raptors.

Conclusions/Significance: This finding represents the first evidence for 
the ancient evolutionary origin of an avian
transmissible disease in non-avian theropod dinosaurs. It also provides 
a valuable insight into the palaeobiology of these
now extinct animals. Based on the frequency with which these lesions 
occur, we hypothesize that tyrannosaurids were
commonly infected by a Trichomonas gallinae-like protozoan. For 
tyrannosaurid populations, the only non-avian dinosaur
group that show trichomonosis-type lesions, it is likely that the 
disease became endemic and spread as a result of
antagonistic intraspecific behavior, consumption of prey infected by a 
Trichomonas gallinae-like protozoan and possibly
even cannibalism. The severity of trichomonosis-related lesions in 
specimens such as Tyrannosaurus rex FMNH PR2081 and
Tyrannosaurus rex MOR 980, strongly suggests that these animals died as 
a direct result of this disease, mostly likely through

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