Perleidiformes
Fossil of Aetheodontus besanensis.
- Madagascar, Europe, Russia, Greenland, Svalbard, North America, Australia.
The Perleidiformes are a group of extinct bony fish of the subclass of Knorpelganoiden ( Chondrostei ), who lived from the Triassic to the Lower Jurassic.
Features
They are increasingly developed a physique that corresponds to the more advanced ray-finned fishes ( Actinopterygii ). In contrast to more primitive Knorpelganoiden the caudal fin is almost exclusively supported by fin rays. The muscle -based Schwanzflossenlobus is greatly reduced. The morphology of the jaw bone shows similarities with the Neuflossern ( Neopterygii ) and other, more advanced taxa of the ray-finned fishes. The Perleidiformes were rather small fish and were 4 to 23 inches long.
Families
- Cephaloxenidae
- Colobodontidae
- Platysiagidae
- Peltopleuridae
- Cleithrolepidae
- Perleididae
- Platysiagidae