Climatius (from , 'gradation') is an extinct genus of spiny shark. Fossils have been found in both Europe and North America. Climatius was an active swimmer, judging from its powerful caudal fin and abundant stabilizing fins, and probably preyed on other fish and crustaceans. Its lower jaw was lined with sharp teeth which were replaced when worn, but the upper jaw had no teeth. It had large eyes, suggesting that it hunted by sight. It was a small fish, at , and to discourage predators, Climatius sported fifteen sharp spines. There was one spine each on the paired pelvic and pectoral fins, and on the aingle anal and two dorsal fins, and a four pairs without fins on the fish's underside. See also List of acanthodians References Parker, Steve. Dinosaurus: the complete guide to dinosaurs. Firefly Books Inc, 2003. Pg. 60 Acanthodii genera Silurian acanthodians Devonian acanthodians Devonian fish of North America Silurian fish of North America Devonian fish of Europe Silurian fish of Europe Paleozoic life of Nova Scotia Taxa named by Louis Agassiz