Petitcodus shark fossil discovered in Mexico
Roman Vullo
A fossil shark that thrived during the Cretaceous period has been found and has shed light on how sharks hunted and their place on the evolutionary tree.
Fossil shark teeth Ptychodus have been in museums for over 200 years. While some members of this group grew to be enormous, the anatomy of others was largely unknown.
This lack of information left researchers uncertain about the shark’s overall appearance and feeding habits, but the wide, flat teeth suggest it was capable of eating hard-shelled prey.
Recently, Professor Roman Vullo at the University of Rennes in France discovered six well-preserved full-body fossils of Ptychodus in Mexico, placing the shark in the order Lamniformes alongside modern shark species like great whites and basking sharks.
What makes this discovery interesting is that while modern white sharks are known for hunting in open waters, Ptychodus were fast swimmers and voracious eaters in the open ocean, preying on armored pelagic fish like large ammonites and sea turtles.
Despite the small size of the studied specimens, estimated to be less than 3 meters long, researchers believe some members of the genus reached lengths of about 9.7 meters – twice the size of a great white shark. Females tended to be larger, measuring between 4.6 and 4.9 meters in length.
During the Cretaceous period, Ptychodus sharks played a significant role in the marine food chain. They likely competed with large marine reptiles with crushing dentition, which may have led to their extinction before the end-Cretaceous extinction event.
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Source: www.newscientist.com
