Acanthopterygii

Acanthopterygii, an order of Teleostean fishes, distinguished by the presence of unjointed spines in the dorsal, anal, and ventral fins, and the generally separate condition of the lower pharyngeal bones. The order has nineteen divisions, and contains some of the commonest fishes, as the perch, stickleback, sea-bream, mackerel, mullets, gobies, etc. The fossil species of the order are mainly Tertiary, but it has some representatives in the Chalk.