Ptycholepiformes Temporal range:
| |
---|---|
| |
Ptycholepis bollensis fossil | |
Scientific classification
![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | †
Ptycholepiformes Andrews et al. 1967 |
Families | |
|
Ptycholepiformes are an extinct order of prehistoric ray-finned fish that existed during the Triassic period and the Early Jurassic epoch. [1] [2] The order includes the genera Acrorhabdus, Ardoreosomus, Boreosomus, Chungkingichthys, Ptycholepis, and Yuchoulepis. Although several families have been proposed, some studies place all these genera in the same family, Ptycholepididae. [3]
Ptycholepiformes had a widespread distribution during the Early Triassic, but were restricted to mainly Europe and North America afterwards. They are known from both marine and freshwater deposits.
Typical features of ptycholepiforms are the fusiform body covered in rhombic ganoid scales, the anterior position of the dorsal fin. In most coeval ray-fins the dorsal fin has a more posterior position), usually situated opposite to the anal fin. Moreover, ptycholepiforms show a series of elongate, horizontal suborbital bones. The skull is usually relatively large.
The scales are typically equipped with distinct longitudinal ridges. In Ptycholepis, the scales are low, whereas in genera, such as Ardoreosomus and Boreosomus, the scales are deeper. Peg-and-socket articulation between scales is present.
Species reached body sizes between 10 centimetres (0.33 ft) and 45 centimetres (1.48 ft). [4]
The evolutionary relationships of Ptycholepiformes are poorly known, but most cladistic analyses place them outside of the Neopterygii. [5] A close relationship between Ptycholepididae and the Carboniferous to Early Triassic Acrolepididae was proposed based on some similarities, but support from phylogenetic analyses is scarce. [6]
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Ptycholepiformes Temporal range:
| |
---|---|
| |
Ptycholepis bollensis fossil | |
Scientific classification
![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | †
Ptycholepiformes Andrews et al. 1967 |
Families | |
|
Ptycholepiformes are an extinct order of prehistoric ray-finned fish that existed during the Triassic period and the Early Jurassic epoch. [1] [2] The order includes the genera Acrorhabdus, Ardoreosomus, Boreosomus, Chungkingichthys, Ptycholepis, and Yuchoulepis. Although several families have been proposed, some studies place all these genera in the same family, Ptycholepididae. [3]
Ptycholepiformes had a widespread distribution during the Early Triassic, but were restricted to mainly Europe and North America afterwards. They are known from both marine and freshwater deposits.
Typical features of ptycholepiforms are the fusiform body covered in rhombic ganoid scales, the anterior position of the dorsal fin. In most coeval ray-fins the dorsal fin has a more posterior position), usually situated opposite to the anal fin. Moreover, ptycholepiforms show a series of elongate, horizontal suborbital bones. The skull is usually relatively large.
The scales are typically equipped with distinct longitudinal ridges. In Ptycholepis, the scales are low, whereas in genera, such as Ardoreosomus and Boreosomus, the scales are deeper. Peg-and-socket articulation between scales is present.
Species reached body sizes between 10 centimetres (0.33 ft) and 45 centimetres (1.48 ft). [4]
The evolutionary relationships of Ptycholepiformes are poorly known, but most cladistic analyses place them outside of the Neopterygii. [5] A close relationship between Ptycholepididae and the Carboniferous to Early Triassic Acrolepididae was proposed based on some similarities, but support from phylogenetic analyses is scarce. [6]
{{
cite journal}}
: Cite journal requires |journal=
(
help)