Semionotiformes

Fossil of Callipurbeckia notopterus from the Solnhofen limestone.

• Worldwide

The Semionotiformes are an extinct order of bony fish. At the order of the recent gars ( Lepisosteidae ) were counted earlier times that are today but found mostly in the order Lepisosteiformes. Today, three families are recognized, the Semionotidae that Callipurbeckiidae and Macrosemiidae.

Features

Diagnostic features of the Semionotiformes are the lack of Endopterygoid ( a paired dermal bones in the palate of fish ), a frontal three was once more widely than at its greatest width, long and narrow nasals, an annular, bony reinforcement of the orbit that was open in front and its posterior border was formed of narrow or tubular infra orbital bones. The Supra orbital bones ( above the eyes ) were small. The Supracleithrum, a deck bones of the shoulder girdle, is without a concave articular surface for articulation with the Posttemporale. On the ridge between the gills and the sides of the Cleithrum sat one or two rows of teeth. The upper edge of the caudal fin is formed by scale-like fin rays. One or two rows of elongated scales were sitting at the bottom of the caudal peduncle. The scales of the Semionotiformes are still covered by a Ganoinlage.

System

The Semionotiformes form with the billfish -like ( Lepisosteiformes ) and no family assigned to the taxon of the genus Neosemionotus Ginglymodi. The Semionotiformes include all taxa that are more related to Semionotus than Lepidotes, Lepisosteus, Amia Dapedium or.

The following cladogram shows the phylogenetic relationships:

Billfish behaved ( Lepisosteiformes )

Neosemionotus

Callipurbeckiidae

Semionotidae

Macrosemiidae

Luoxiongichthys

Sangiorgioichthys

The high-backed Dapedidae, formerly often considered a family of Semionotiformes be found in recent studies in the core group of Teleostei.