Boulder, CO, USA - Long before whales, the oceans of Earth were roamed by a very different kind of air-breathing leviathan. Snaggle-toothed ichthyosaurs larger than school buses swam at the top of the Triassic Period ocean food chain, or so it seemed before Mount Holyoke College paleontologist Mark McMenamin took a look at some of their remains in Nevada. Now he thinks there was an even larger and more cunning sea monster that preyed on ichthyosaurs: a kraken of such mythological proportions it would have sent Captain Nemo running for dry land. McMenamin will be presenting the results of his work on Monday, 10 October at the Annual Meeting of The Geological Society of America in Minneapolis.
The evidence is at Berlin-Ichthyosaur State Park in Nevada, where McMenamin and his daughter spent a few days this summer. It's a site where the remains of nine 45-foot (14-meter) ichthyosaurs, of the species Shonisaurus popularis can be found. These were the Triassic's counterpart to today's predatory giant squid-eating sperm whales. But the fossils at the Nevada site have a long history of perplexing researchers, including the world's expert on the site: the late Charles Lewis Camp of U.C. Berkeley.
"Charles Camp puzzled over these fossils in the 1950s," said McMenamin. "In his papers he keeps referring to how peculiar this site is. We agree, it is peculiar."
Camp's interpretation was that the fossils probably represented death by an accidental stranding or from a toxic plankton bloom. But no one had ever been able to prove that the beasts died in shallow water. In fact more recent work on the rocks around the fossils suggest it was a deep water environment, which makes neatly arranged carcasses even more mysterious.
This question -- shallow or deep ocean death -- is what attracted McMenamin to the site.
"I was aware that anytime there is controversy about depth, there is probably something interesting going on," McMenami
|Contact: Christa Stratton|
Geological Society of America