Cladoselache

Cladoselache species

Today's Shark is the largest one that we have talked about so far, and it is also the oldest. Cladoselache is the name of a genus containing eight different Shark species, all of which lived during the Devonian Period, around 370 million years ago.

Sharks have been around for hundreds of millions of years, and the Cladoselache Sharks are some of the best known of the ancient species. This is because many of their fossils were very well preserved in a formation near Lake Erie. Some of these fossils are so detailed that we know their stomach contents!

These extinct sea creatures are interesting not only because they lived a very, very long time ago, but also because they had some interesting anatomical features. For one, they almost completely lacked scales. The only scales it had were found on the tips of the fins, and around the mouth and eyes. Secondly, these Sharks lacked "claspers"-- the reproductive organs that are found not only in modern sharks, but in many other ancient species as well. Scientists are still unsure how they specifically reproduced. Finally, the Cladoselache Sharks had smooth, blunt teeth. Rather than tear apart their prey, they grasped it and swallowed it whole.

Cladoselache Sharks were probably very fast and agile, based on their body shape, dorsal fins, and large tail fin. They were high speed predators who also needed to be quick in order to avoid becoming prey themselves. Sharks weren't the only large predators swimming the seas-- this was the time of the 30ft Dunkleosteus as well!

There are no close relatives of the Cladoselache Sharks left today. All other genera within the family are extinct, and that family was the only one within the entire order.

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Status : Extinct for around 370 million years
Location : North America
Size : Length up to 6ft (1.8m)

Classification : Phylum : Chordata -- Class : Chondrichthyes -- Order : †Cladoselachiformes
Family : †Cladoselachidae -- Genus : †Cladoselache