Semionotiformes
| Semionotiformes | ||||||||||||
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Fossil of Callipurbeckia notopterus |
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| Temporal occurrence | ||||||||||||
| Anisium ( Middle Triassic ) to Cenomanium (Lower Upper Cretaceous ) | ||||||||||||
| 247.2 to 93.9 million years | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Semionotiformes | ||||||||||||
| Arambourg & Bertin , 1958 |
The Semionotiformes are an extinct order of bony fish . In the past, the recent bone pike (Lepisosteidae) were often included in the order, but today they are mostly placed in the order Lepisosteiformes . Today three families are recognized, the Semionotidae , the Callipurbeckiidae and the Macrosemiidae .
features
Diagnostic features of the Semionotiformes are the absence of the endopterygoid (a pair of skin bones in the palate of fish), a frontal that was three times longer than at its greatest width, long and narrow nasals , a ring-shaped, bony reinforcement of the orbit that was open at the front posterior margin was formed by narrow or tubular infraorbital bones. The supraorbital bones (above the eyes) were small. The supracleithrum, a cover bone of the shoulder girdle, has no concave articular surface for articulation with the post-temporal. On the ridge between the gills and the sides of the cleithrum sat a row or two of teeth. The upper edge of the caudal fin is formed by scale-like fin rays. A row or two of elongated scales sat at the bottom of the tail peduncle. The scales of the semionotiformes are still covered by a gano inlay .
Systematics
The Semionotiformes form the taxon of the Ginglymodi with the bonefish-like (Lepisosteiformes) and the genus Neosemionotus, which is not assigned to any family . The Semionotiformes include all taxa that are more related to Semionotus than to Lepidotes , Lepisosteus , Dapedium or Amia .
The following cladogram shows the relationships:
| Ginglymodes |
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literature
- Adriana López-Arbarello: Phylogenetic Interrelationships of Ginglymodian Fishes (Actinopterygii: Neopterygii). PLoS ONE , July 2012, doi: 10.1371 / journal.pone.0039370
