Rhizodontida
- Europe, North America, Australia, Antarctica
The Rhizodontidae are an extinct group of bony fish from the class of meat -finned fishes ( Sarcopterygii ). They lived from the Middle Devonian to Pennsylvanian offshore in the sea and in fresh water, and are known by several fragments of a fossil and only completely preserved.
The first fossil traditional form is Notorhizodon from the Middle Devonian of southern Victoria land, Antarctica, which was discovered in the early 1970s. The find consisted of parts of the skull, the lower jaw and the shoulder girdle. Notorhizodon was a big, probably three feet long expectant predator. The only other Rhizodontier from the Devonian is Sauripterus from North America, one of the pectoral fin skeleton is obtained, which suggests a fish of similar length to Notorhizodon.
During the Carboniferous the Rhizodontia reached their greatest biodiversity. Rhizodus from Scotland is known only from a one meter long lower jaw, which was occupied by a maximum of 22 cm long teeth. It is estimated that the fish was 6 to 7 feet long. The smallest species, Strepsodus anculonamensis reached a length of 50 cm. From her the only fully preserved fossil of a Rhizodontiers comes. The skull of Barameda from Mansfield Shire in southern Australia shows similarities with the Osteolepiformes. At the beginning of the Permian, the Rhizodontia died out.
Features
The Rhizodontia were predators, and probably ate large fish, amphibians and aquatic Temnospondylen. The term " Rhizodontia " means " Wurzelzähner " her fangs sat deep in the pines. The teeth of some large Rhizodontier were laterally flattened. All fins were beschuppt almost to the brim. The pectoral fins were strong and of good bone (humerus, ulna, radius) were supported. Dorsal and ventral fins were small, the tail fin diphyzerk. They had two pairs of nostrils, a Choane but seemed to be missing.
Genera
- Barameda
- Gooloogongia
- Notorhizodon
- Pycnotenion
- Propycnotenion
- Rhizodus
- Sauripterus
- Screbinodus
- Strepsodus