Eosuchia

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Eosuchia

Eosuchians are an extinct order

Order (biology)

In Biological classification used in biology, the order is a taxonomic rank between class and family . The superorder is a rank between class and order....
of diapsid

Diapsid

Diapsids are a group of reptiles that developed two holes in each side of their skulls, about 300 million years ago during the late Carboniferous period....
reptiles. Depending on which taxa are included the order may have ranged from the late Carboniferous

Carboniferous

The Carboniferous is a geologic period that extends from the end of the Devonian period, about 359.2 ? 2.5 annum , to the beginning of the Permian period, about 299.0 ? 0.8 Ma ...
to the Eocene

Eocene

The Eocene Geologic time scale is a major division of the geologic timescale and the second epoch of the Palaeogene period in the Cenozoic era....
but the consensus is that eosuchians are confined to the Permian

Permian

The PermianThe term "Permian" was introduced into geology in 1841 by Sir Roderick Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian system" after the ancient kingdom...
and Triassic

Triassic

The Triassic is a geologic period that extends from about 251 to 199 annum . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic....
.

A definition for inclusion in the order is difficult: it is almost easier to list the primitively-diapsid reptiles that have not been included at one time or another. The order has almost been treated as a dustbin for diapsids that are not obviously lepidosaurian or archosaurian.

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Encyclopedia

Eosuchians are an extinct order

Order (biology)

In Biological classification used in biology, the order is a taxonomic rank between class and family . The superorder is a rank between class and order....
of diapsid

Diapsid

Carboniferous

The Carboniferous is a geologic period that extends from the end of the Devonian period, about 359.2 ? 2.5 annum , to the beginning of the Permian period, about 299.0 ? 0.8 Ma ...
to the Eocene

Eocene

Permian

Triassic

Younginiformes

Younginiformes is a replacement name for the taxon Eosuchia, proposed by Alfred Romer in 1947.The Eosuchia having become rather a dustbin for many probably distantly-related primitive diapsid reptiles ranging from the late Carboniferous to the Eocene, Romer proposed that this be replaced by Younginiformes, to include the Younginidae and a v...
to be applied strictly to those forms with the primitive diapsid form, in particular, a complete lowermost arch as the quadratojugal and jugal bones of the skull meet.

The one constant eosuchian has been Younginia
Younginia

Younginia is an extinct genus of small, lizard-like reptile from the Late Permian of South Africa. This, and a few related forms, make up the family Younginidae, within the Order Eosuchia ....
, a small lizard-shaped reptile from the Upper Permian of South Africa

South Africa

The Republic of South Africa, also known by Official names of South Africa, is a country located at the southern tip of the continent of Africa....
. This and a couple of other genera, which may or may not be synonymous with Younginia, make up the family Younginidae.

The tangasaurids, a family that includes forms apparently adapted for swimming in fresh water, is also usually included.

In some phylogenies Eosuchia has been treated (probably erroneously) as a sister lepidosaur taxon to Squamata

Squamata

Squamata, or the scaled reptiles, is the largest recent order of reptiles, including lizards and snakes. Members of the order are distinguished by their skins, which bear horny scale or shields....
and Rhynchocephalia.

Classification

Eosuchia s.s. (Syn:Younginiformes
Younginiformes

Younginiformes is a replacement name for the taxon Eosuchia, proposed by Alfred Romer in 1947.The Eosuchia having become rather a dustbin for many probably distantly-related primitive diapsid reptiles ranging from the late Carboniferous to the Eocene, Romer proposed that this be replaced by Younginiformes, to include the Younginidae and a v...
) ?Noteosuchus

Family: Galesphyridae

Galesphyrus

Family: Younginidae

Heleosuchus Younginia
Younginia

Younginia is an extinct genus of small, lizard-like reptile from the Late Permian of South Africa. This, and a few related forms, make up the family Younginidae, within the Order Eosuchia ....

Family: Tangasauridae

Tangasauridae

Tangasauridae is a Family of Eosuchia Diapsida. Specimens have been found that are of Permian to Early Triassic in age from the Sakamena Group of western Madagascar....

Hovasaurus
Hovasaurus

Hovasaurus is an extinct genus of diapsid reptile belonging to the Order Eosuchia. It was about 50 cm long, and lived in what is now Madagascar....
Tangasaurus Thadeosaurus
Thadeosaurus

Thadeosaurus is an extinct genus of diapsid reptile belonging to the Order Eosuchia. It was about 60 cm long.Two thirds of Thadeosauruss length belonged to its long tail....
Kenyasaurus