Wednesday, January 09, 2013

Uber Sized Ichythosaur in Anisian Triassic

An international team of scientists has described a fossil marine predator measuring 8.6 meters in length (about 28 feet) recovered from the Nevada desert in 2010 as representing the first top predator in marine food chains feeding on prey similar to its own size. A paper with their description will appear the week of January 7, 2013 in the EE (early electronic) issue of Proceedings of the National Academy of Sciences.

Scientists who studied the fossil include lead author Dr. Nadia Fröbisch and Prof. Jörg Fröbisch (both at Museum für Naturkunde Leibniz-Institut für Evolutions- und Biodiversitätsforschung), Prof. P. Martin Sander (Steinmann Institute of Geology, Mineralogy, and Paleontology, Division of Paleontology, University of Bonn), Prof. Lars Schmitz (W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, California) and Dr. Olivier Rieppel (The Field Museum, Chicago, Illinois).

The 244-million-year-old fossil, named Thalattoarchon saurophagis (lizard-eating sovereign of the sea) is an early representative of the ichthyosaurs, a group of marine reptiles that lived at the same time as dinosaurs and roamed the oceans for 160 million years. It had a massive skull and jaws armed with large teeth with cutting edges used to seize and slice through other marine reptiles in the Triassic seas. Because it was a meta-predator, capable of feeding on animals with bodies similar in size to its own, Thalattoarchon was comparable to modern orca whales.

Remarkably, only eight million years prior to the appearance of Thalattoarchon, a severe extinction at the end of the Permian period killed as many as 80 to 96 percent of species in the Earth's oceans. The rise of a predator such as Thalattoarchon documents the fast recovery and evolution of a modern ecosystem structure after the extinction.

They are right.  This has enormous implications for the recovery after the PT Extinction.  You can't have a monster sized carnivore without lots to feed it.  It flies in the face of what Benson (and Sarda!) have been saying.  More and more the Triassic does not appear to have been what folks have thought.

Hat tip to Chinleana

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