Xenasaphus devexus is a member of the animal class of Trilobites, a large group of long extinct marine arthropods that lived during most of the Paleoz

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Xenasaphus devexus is a member of the animal class of Trilobites, a large group of long extinct marine arthropods that lived during most of the Paleozoic era. They are well known on account of the aptness of their hard scales for fossilisation and many fossils are found all over the world. This sample shows an accumulation from Middle Ordovician rocks nearby St Petersburg, Russia, dating back approximately 450 million years. The variety in size and age, and the breakage of the shells indicates that in this case there must have been catastrophic circumstances that led to mass mortality of the specimen. Actual width of this plaque is 40 cm.

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Photo credit: © DIRK WIERSMA/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: arthropods, fossilisation, marine, mass-mortality, ordovician, paleozoic, petersburg, st, trilobites, xenasaphus-devexus