Caturus furcatus

Caturus furcatus Agassiz 1834

    Upper Jurassic

    Tithonian (Malm zeta)

    Solnhofen

    Germany

    The Caturidae are represented in the Solnhofen Formation by at least four species:

    Caturus furcatus Agassiz 1834, Caturus giganteus Wagner, 1851, Caturus pachyurus Agassiz, 1833 (all from Solnhofen) and Caturus bellicianus Thiollière 1852 from Solnhofen, Germany and Cerin, France.

    The last two species were transferred to the revived sister genus Amblysemius (now Amblysemius pachyurus and Amblysemius bellicianus).

    Caturus was clearly a predator as evidenced by its mouth full of sharp teeth. It was a notable fast swimmer possessing an elongated, somewhat thickset body with slender head. Together with its only sister genus Amblysemius, Caturuswas a member of the extinct Halecomorpha family Caturidae. It appears that the halecomorph Liodesmus, known from Solnhofen only, is related to the Caturids, rather than the Amiiforms, as has been usually surmised. Once a diverse major group of bony fishes, the Halecomorpha have only one surviving member, the bowfin (Amia calva) of eastern North America. Living bowfins are remarkably hardy since they have a swim bladder that opens into their esophagus so they can gulp air, and hence survive in water with low oxygen. Caturus was a primitive species of fish that thrived during the Jurassic Period but went extinct by the Lower Cretaceous Period. Caturus possessed ganoid scales that are more cycloid in nature and as a member of the holosteans a bony skeleton with a partially ossified vertebral column. The head is short an equipped with powerfully toothed jaws. The dorsal fin is pointed and attached just posterior to the body's midpoint. anal fin is attached somewhat more to the rear. The caudal fin is large and deeply divided.

    Less than 5% of all adult Caturus show peculiar anal fins with two small outgrows of unknown function (such as seen here).

    With a hefty 50cm or 20" in length, this is clearly an adult specimen.