"Newly discovered fossil fish material from the Cretaceous Dinosaur Park Formation of Alberta, Canada, documents the presence of a tropical fish in this northern area about 75 million years ago (Ma). The living relatives of this fossil fish, members of the Characiformes including the piranha and neon tetras, are restricted to tropical and subtropical regions, being limited in their distribution by colder temperatures," scientists writing in the journal Proceedings of the Royal Society B - Biological Sciences report (see also Biology).
"Although characiform fossils are known from Cretaceous through to Cenozoic deposits, none has been reported previously from North America. The modern distribution of characiforms in Mexico and southern Texas in the southernmost United States is believed to have been the result of a relatively recent colonization less than 12 Ma. The new Canadian fossils document the presence of these fish in North America in the Late Cretaceous, a time of significantly warmer global temperatures than now. Global cooling after this time apparently extirpated them from the northern areas and these fishes only survived in more southern climes," wrote M.G. Newbrey and colleagues.
The researchers concluded: "The lack of early Cenozoic characiform fossils in North America suggests that marine barriers prevented recolonization during warmer times, unlike in Europe where Eocene characiform fossils occur during times of global warmth."
Newbrey and colleagues published their study in Proceedings of the Royal Society B - Biological Sciences (Seventy-five-million-year-old tropical tetra-like fish from Canada tracks Cretaceous global warming. Proceedings of the Royal Society B - Biological Sciences, 2009;276(1674):3829-3833).
Additional information can be obtained by contacting M.G. Newbrey, Royal Tyrrell Museum Palaeontol, POB 7500, Drumheller, AB T0J 0Y0, Canada.
The publisher of the journal Proceedings of the Royal Society B - Biological Sciences can be contacted at: Royal Society, 6-9 Carlton House Terrace, London SW1Y 5AG, England.
Keywords: Country:Canada, Country:Canada, Life Sciences, Biological Science.
This article was prepared by Science Letter editors from staff and other reports. Copyright 2009, Science Letter via NewsRx.com.
"Research results from M.G. Newbrey and colleagues update understanding of biology." Science Letter 24 Nov. 2009: 562. Academic OneFile. Web. 26 Nov. 2009.
Gale Document Number:A212487228
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