アメリカ自然史博物館のインスタグラム(amnh) - 6月17日 01時08分

It’s time for ‪‎#TrilobiteTuesday, and this week is an amazing example of “mass mortality”– a plate covered with 3 inch-long Homotelus bromidensis from the 430 million year old Ordovician rocks of Oklahoma. Scientists have long speculated whether such fossilized groupings represent a social gathering, a mating assemblage or merely the results of an ancient tidal estuary drying up, leaving its Paleozoic inhabitants quite literally high and dry. While such trilobite mass mortality plates are unusual in the fossil record, they have been found in such diverse locations as Portugal, Morocco and Canada.

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