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Re: New PLOS One paper on T rex infections

while we are mentioning new PLoS ONE papers:

Dragon's Paradise Lost: Palaeobiogeography, Evolution and Extinction of the 
Largest-Ever Terrestrial Lizards (Varanidae)


--- On Wed, 9/30/09, Dan Chure <danchure@easilink.com> wrote:

> From: Dan Chure <danchure@easilink.com>
> Subject: New PLOS One paper on T rex infections
> To: "DML" <dinosaur@usc.edu>
> Date: Wednesday, September 30, 2009, 9:27 AM
> New paper available at
> http://www.plosone.org/article/info:doi/10.1371/journal.pone.0007288#top
> Common Avian Infection Plagued the Tyrant Dinosaurs
> Ewan D. S. Wolff1*, Steven W. Salisbury2,3*, John R.
> Horner4, David J. Varricchio5
> 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 âSueâ) 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 
at 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
> starvation.