Tristichopteridae
Artistic reconstruction of Eusthenopteron live on shore, at the Museum of Natural History at Michigan State University.
- Europe, Russia, North America, Greenland
- Antarctica, Australia
The Tristichopteridae ( Syn: Eusthenopteridae ) are an extinct fish family from the class of meat -finned fishes ( Sarcopterygii ), which occurred from the Middle Devonian to Late Devonian. Fossils of the family were both in the northern hemisphere, the former continent Laurussia, as well as in Antarctica and found in Australia ( formed in Devon together with Africa and South America the Gondwana supercontinent ). The Tristichopteridae represent the most species-rich radiation tetrapodomorpher fish is first developed in Laurussia and were probably spread during the late Devonian world. Various Tristichopteriden different size came at the same time before the same place and have different ecological niches occupied. At the end of the Devonian extinction event they fell a victim. Your Ecological niches were occupied by Fleischflossern from the families of Megalichthyidae and Rhizodontidae.
The Tristichopteridae Eusthenopteron, one of the best known and most researched extinct fish that has been researched intensively by the Swedish Paläozoologen Erik Jarvik and of great importance for the understanding of the gangway of land vertebrates ( Tetrapoda ) has heard.
Features
The Tristichopteridae were medium-sized ( Tristichopterus, 30 cm) to very large fish, the biggest forms ( Hyneria ) could be several meters long, had up to 30 cm long teeth and were in their faunal the largest predatory fish. The Tristichopteridae had a powerful formed fin skeleton, which probably allowed them briefly to leave the water. In the skeleton of the front flippers, the ansetzten deep, can the elements located towards the body of the subsequent foreleg of land vertebrates, humerus, radius and ulna, already recognize. The trunk from the outward parts of the bones were flattened. The basin had long, tapering pubic rami ( Ramui pubis ) that might be met in a cartilaginous symphysis. The pelvic fins contain the most important bones of the hind legs, femur, tibia and fibula. Ankle bones ( tarsal bones ) and toe can not yet identify themselves. The limbs were oriented to the side and able to be moved by only about 20 to 25 ° back and forth. The anal fin was sitting on a basal, fleshy stalk. The caudal fin was three-lobed ( triphycerk ), outwardly always symmetrical with basal forms initially unbalanced and in later forms. In the family only modern roundhouse occurred with a central projection on the inside and without Cosmi layer.
Genera
- Cabonnichthys, Upper Devonian of New South Wales, Australia.
- Edenopteron, Upper Devonian of New South Wales, Australia.
- Eusthenodon, Famennian of Greenland, Pennsylvania, Belgium, Russia, Australia and South Africa.
- Eusthenopteron, Frasnian of eastern Canada, Latvia and the UK.
- Heddleichthys, Famennian of Scotland.
- Hyneria, Famennian of Pennsylvania.
- Jarvikina, Frasnian of the Baltic States.
- Langlieria, Famennian of Belgium.
- Mandageria, Upper Devonian of New South Wales.
- Notorhizodon, Givetian of Antarctica.
- Platycephalichthys, Upper Devonian of Latvia.
- Tristichopterus, Givetian of the Orkney and Shetland Islands.
System
The Tristichopteridae were in the past associated with the Osteolepiformes, a Fleischflossergruppe, which is considered paraphyletic today. Today they form with some other taxa that are even closer to the land vertebrates, the order Eotetrapodiformes. The sister taxon of Tristichopteridae is Spodichthys, which is very similar to the Tristichopteridae, but differs from them by the position of Extratemporalknochens ( skull bone ).
The systematic position shows the following cladogram ( no longer belongs to the Platycephalichthys Tristichopteridae here):
Elpistostegalia → terrestrial vertebrates ( Tetrapoda )
Platycephalichthys
Tinirau
Spodichthys
Tristichopterus
Eusthenopteron
Jarvikina
Notorhizodon
Heddleichthys
Cabbonichthys
Mandageria
Langlieria
Eusthenodon
Megalichthyidae
Medoevia
Osteolepis
Gyroptychius
Rhizodontidae
Kenichthys