Cladoselache is the first group to evolve that we would recognise as sharks, but they may in fact have been a type of chimaera. ©No bu Tamura/Wikimedia Commons The Carboniferous Period, which began ...

This species is part of a group informally called “chipmunk sharks”, due to their small size and unusual dentition. These ...

These sharks grew to just 3 to 4 inches (7.5 ... which are made up of rocks that have preserved marine sediment from the Carboniferous period (358.9 million to 298.9 million years ago).