Ichthyolith

A Ichthyolith ( ancient Greek ἰχθύς ichthys "fish", AltGr. Lithos "stone" ) is the fossil of a fully or partially (eg teeth or scales) obtained fish. The fossil dorsal-fin spines of primitive shapes fish ( sharks ( dogfish sharks ), especially Paleozoic age are Ichthyodorulith ( altgr. Dory " skewer ", " lance " ) called ..