Osteolepiformes, also known as Osteolepidida, is a group of

prehistoric Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use o ...

lobe-finned fishes Sarcopterygii (; )—sometimes considered synonymous with Crossopterygii ()—is a clade (traditionally a class (biology), class or subclass) of vertebrate animals which includes a group of bony fish commonly referred to as lobe-finned fish. The ...

which first appeared during the

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

period. The

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

contains the families Canowindridae, Megalichthyidae, Osteolepididae and

Tristichopteridae Tristichopterids (Tristichopteridae) were a diverse and successful group of fish-like tetrapodomorphs living throughout the Middle and Late Devonian. They first appeared in the Eifelian stage of the Middle Devonian. Within the group sizes ranged ...

, in addition to several monotypic families. The order is generally considered to be

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

because the characters that define it are mainly attributes of stem tetrapodomorphs. The following taxonomy is based on Borgen & Nakrem, 2016: * Order Osteolepiformes ** Suborder Osteolepidoidei *** Family Osteolepididae *** Family Thursiidae *** Family Megalichthyidae ** Suborder Cyclolepidoidei *** Superfamily Eopodoidea **** Family Chrysolepididae **** Family Gyroptychiidae **** Family Panderichthyidae (incl.

Elpistostegalia Elpistostegalia is a clade containing ''Panderichthys'' and all more derived Tetrapodomorpha, tetrapodomorph taxa. The earliest elpistostegalians, combining fishlike and tetrapod-like characters, such as ''Tiktaalik'', are sometimes called fisha ...

) **** Family

*** Superfamily Parapodoidea **** Family Canowindridae **** Family Medoevididae *** Superfamily Rhizodontoidea Below is a

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

showing the paraphyly of Osteolepiformes compiled and modified from Ahlberg and Johanson (1998). See also Swartz (2012). Osteolepiformes is marked by the green bracket.

References

External links

Tree of Life
Tetrapodomorph orders Paraphyletic groups {{paleo-tetrapodomorph-stub