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 Period may refer to: Common uses * Period (punctuation) * Era, a length or span of time *Menstruation, commonly referred to as a "period" Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (o ...

. 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 The Canowindridae are a family of prehistoric tetrapodomorphs which lived during the Devonian period (Famennian stage, about 374 to 359 million years ago). Fossils belonging to this family have been found in Australia, Antarctica, and Europe. P ...

Megalichthyidae Megalichthyidae is an extinct family (biology), family of tetrapodomorphs which lived from the Middle Devonian, Middle–Late Devonian to the Early Permian. They are known primarily from freshwater deposits, mostly in the Northern Hemisphere (Eur ...

, 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 ''Thursius'' is a genus of prehistoric lobe-finned fish Sarcopterygii (; )—sometimes considered synonymous with Crossopterygii ()—is a clade (traditionally a class or subclass) of vertebrate animals which includes a group of bony fish com ...

*** Family

** Suborder Cyclolepidoidei *** Superfamily Eopodoidea **** Family

Chrysolepididae ''Chrysolepis'' is a genus of prehistoric marine lobe-finned fish that lived during the Late Devonian period. It contains a single species, ''C. orlensis'', known from the middle Famennian of Oryol Oblast Oryol Oblast (), also known as Orlov ...

**** Family Gyroptychiidae **** Family

Panderichthyidae ''Panderichthys'' is a genus of extinct sarcopterygian (lobe-finned fish) from the late Devonian period, about 380 Mya. ''Panderichthys'', which was recovered from Frasnian (early Late Devonian) deposits in Latvia, is represented by two species. ...

(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

**** 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