Porolepiformes is an
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...
of
prehistoric
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of ...
lobe-finned fish which lived during the
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...
period (about 416 to 359
million years ago). The group contains two
families:
Holoptychiidae
Holoptychiidae is an extinct family of lobe-finned fishes which lived during the Devonian period. At least one genus, ''Laccognathus'', is thought to have been amphibious
Amphibious means able to use either land or water. In particular it may ...
and
Porolepididae.
Porolepiformes was established by the Swedish paleontologist
Erik Jarvik, and were thought to have given rise to the
salamanders and
caecilians independently of the other
tetrapods. He based this conclusion on the shapes of the snouts of the aforementioned groups. This view is no longer in favour in
Paleontology.
Jarvik also claimed the existence of
choanae in porolepiformes which linked them to tetrapods, but this has remained controversial. Recent phylogenetic reconstruction places porolepiformes close to lungfishes.
More recent evidence has shown that at least one genus ''
Laccognathus
''Laccognathus'' is an extinct genus of amphibious lobe-finned fish from Europe and North America. They existed from the Middle Devonian to the Late Devonian (around 397.5 to 360 mya). The name comes from Greek for 'pitted jaw'.
Description
Spe ...
'' was most likely
amphibious
Amphibious means able to use either land or water. In particular it may refer to:
Animals
* Amphibian, a vertebrate animal of the class Amphibia (many of which live on land and breed in water)
* Amphibious caterpillar
* Amphibious fish, a fish ...
.
Phylogeny
Mikko's Phylogeny Archive
References
Prehistoric lobe-finned fish
Prehistoric fish orders
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