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Fungi and the Dinosaur Extinction: A New Article



This is a new one. . .basically, they're saying that dinosaurs were killed
by mushrooms. Ok, so that's a bit of an exaggeration. But they seem to have
overlooked new views on probable "endothermic" metabolism for many
dinosaurs.

Even if the role of fungi in dinosaur extinction isn't so likely, the idea
of fungal resistance as a major factor behind endothermy is an interesting
one.

Arturo Casadevall. In Press, Corrected Proof Available Online 5 January
2005. Fungal virulence, vertebrate endothermy, and dinosaur extinction: is
there a connection? Fungal Genetics and Biology.

Abstract
Fungi are relatively rare causes of life-threatening systemic disease in
immunologically intact mammals despite being frequent pathogens in insects,
amphibians, and plants. Given that virulence is a complex trait, the
capacity of certain soil fungi to infect, persist, and cause disease in
animals despite no apparent requirement for animal hosts in replication or
survival presents a paradox. In recent years studies with amoeba, slime
molds, and worms have led to the proposal that interactions between fungi
and other environmental microbes, including predators, select for
characteristics that are also suitable for survival in animal hosts. Given
that most fungal species grow best at ambient temperatures, the high body
temperature of endothermic animals must provide a thermal barrier for
protection against infection with a large number of fungi. Fungal disease is
relatively common in birds but most are caused by only a few thermotolerant
species. The relative resistance of endothermic vertebrates to fungal
diseases is likely a result of higher body temperatures combined with immune
defenses. Protection against fungal diseases could have been a powerful
selective mechanism for endothermy in certain vertebrates. Deforestation and
proliferation of fungal spores at cretaceous-tertiary boundary suggests that
fungal diseases could have contributed to the demise of dinosaurs and the
flourishing of mammalian species. 

Keywords: Fungi; Pathogenic; Endothermy; Ectothermy; Dinosaur; Amoebae