German fossil find could rewrite pre-history

BERLIN -- The discovery of a new species of marine reptile in Germany may change the whole of current extinction theory, including why we think some animals manage to survive cataclysmic natural events.
Written by Shannon Smith, Correspondent (Berlin)

BERLIN -- The discovery of a new prehistoric species in Germany is challenging current extinction theory, an international team of researchers says.

Scientists from Belgium, the UK and Germany worked to identify the unique ichthyosaur fossil remains discovered seven years ago in Lower Saxony, according to a report published in open-access journal PLoS ONE.

The sharp-toothed, dolphin-like creature, which lived some 65 to 130 million years ago during the Cretaceous period, was previously thought to have gone extinct during the Jurassic period - millions of years earlier.

"It’s a spectacular find,” Braunschweig's State Natural History Museum director Ulrich Joger told the web news portal The Local. “With this, an entire extinction theory will be questioned.”

Experts say extinction theory is important in understanding how and why various animal species have either survived or been wiped out by prehistoric mass extinction events, for example the various meteor strikes that are thought to have resulted in climate change and the eventual extinction of many species:

"If we can [understand the mechanisms behind the survival or demise of a species], using fossils like these as our indicators, and the tools of interplanetary sciences," Dave Armstrong of EarthTimes.org explained, "[man kind's evolutionary successors] could be the only form of life to survive their projected demise. At least the ichthyosaur has now managed an extra 50 million years."

This newest ichthyosaur fossil, which was uncovered during a dig in 2005, has been named Acamptonectus densus, loosly translating to "tightly-packed rigid swimmer", researcher and report co-author Darren Naish said. The fossil was compared with two other ichthyosaur specimens discovered in England in 1958 and 1985 to reveal three instances of ichthyosaur survival into the late Cretaceous period.

"The last ichthyosaurs, then, were not lone representatives of a single lineage," Naish said of his team's findings, "rather, 'the last’ ichthyosaurs were actually taxonomically diverse and morphologically disparate...' (Fischer et al. 2012, p. 20)."

Naish says the question now is whether (and why) ichthyosaurs were "highly resistant to whatever events caused [the] biological crisis" at the Jurassic-Cretaceous Boundary (JCB), which apparently spelled doom for so many other marine reptile groups.

"Gradually, we are revising our views of what marine reptile diversity was like in the Cretaceous," Naish said.

Photo: Flickr/mhaller1979

This post was originally published on Smartplanet.com

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