The Chondricthyans (including the sharks and rays) have been around and keeping the ocean's ecosystems healthy for about 420 Million Years. Today, in celebration of this, I've decided to do a little fun post and list the eight times in Earth's history truly massive chondricthyans have emerged. Hope you all enjoy!!!
The First is the Devonian, where there is at least one confirmed fossil (CMNH 5238) of a large currently unnamed Ctenacanthiform shark that reached lengths of 4.2-5 meters (13-16 feet) in length.
https://www.mdpi.com/1424-2818/15/3/318
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