Named By: Louis Agassiz - 1845.
Synonyms: Ctenacanthus latispinosus, Euthacanthus gracilis, Euthacanthus grandis, Euthacanthus macnicoli, Euthacanthus macnicolli.
Classification: Chordata, Acanthodii, Climatiiformes, Climatiidae.
Species: C. reticulatus (type), C. gracilis, C. grandis, C. latispinosus, C. macnicoli, C. scutiger, C. uncinatus.
Size: 7.5 centimetres long.
Known locations: Europe. North America.
Time period: Early Devonian.
Fossil representation: Many known specimens.
a 'spiny shark' Climatius was not a true shark
but was still
related to them. Climatius was probably an open
water hunter of
smaller fish, and two clues to indicate this are both the strongly
developed caudal fin and the large pectoral fins. As the caudal fin
(loosely dubbed the tail) propelled Climatius
forward it would also
have the effect of putting the fish into a 'nosedive' towards the
bottom. To counter this effect the pectoral fins act like hydrofoils
to keep Climatius in a straight line as it swims
forward. This may
sound like a lot to infer for a fish that is only known from fossils,
but this principal actually applies to all fish.
Climatius was probably a visually orientated predator as indicated by its large forward facing eyes. Once these located potential prey, the powerful tail would be employed to give chase and close the distance. Climatius would then use its small but sharp teeth to seize its prey, although rather surprisingly the teeth were only present in their lower jaw. This may have been so that it was easier to manipulate prey in the mouth so that it could be swallowed. Like in sharks, Climatius replaced its teeth as they became worn.
Not only did Climatius have the standard complement of strong spines present in the major fins (pectoral, pelvic, anal and both dorsal), it also had an additional four pairs of spines that ran along the underside. With a combined total of fifteen hard spines Climatius was significantly more protected than the related Acanthodes, and would have been a difficult mouthful for predators.
- Distribution of vertebrates in the Silurian of Estonia - E. Mark-Kurik - 1969.