Acanthodes

Science Name

Ferocactus acanthodes

Description

The popular name"spiny sharks" is really a misnomer for these early jawed fishes.The name was coined because they were generally hark-shaped, with a streamlined body, paired fins and a strongly upturned tail.

Habitat

Acanthodes was bigger than its past links; some members of its group reached lengths of over 6 ft 6 in/2m. Acanthodes was also less prickly than past forms. Its paired pectoral fins still had stout spines, as did the large anal fin. But there was only one spiny dorsal fin, set far back near the tail, and the pair of the ribbon like pelvic fins that ran along the belly each had a single spine. Thus, Acanthodes only had 6 fin spines on its body, compared with the 15 spines of its prickly relative, Climatius (above).

Behaviour

Acanthodes was larger than its earlier relatives,some members of its group reached lengths of over 6 ft 6 in/2m. Acanthodes was also less spiny than earlier forms.

Life History

Acanthodes was a member of the last group of spiny sharks to evolve. They had no teeth in their jaws,but the gills were equipped with long bony "rakers" made of toothlike spikes.Acanthodes and its relatives were probably filter- feeders, sieving tiny, planktonic animals through their gills.

Region Found

Australia (Victoria),Europe (Czechoslovakia, England,Germany, Scotland and Spain) and North America (Illinois, Kansas, Pennsylvania and West Virginia)