Neodiapsida

Neodiapsids
Temporal range:
Guadalupian - Holocene, 270–0Ma
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Diapsida
Clade: Neodiapsida
Benton, 1985
Subgroups

Claudiosaurus
Ichthyosauromorpha
Weigeltisauridae
Younginiformes
Archosauromorpha
Lepidosauromorpha

Neodiapsida is a clade, or major branch, of the reptilian family tree and includes all diapsids apart from some early primitive types known as Araeoscelidia.

In phylogenetic systematics, they are variously defined as the common ancestor and all its descendants of Younginiforms and "crown diapsids" (the common ancestor of lizards, crocodilians and birds, and all their descendants) [Callaway 1997], or all diapsids that are more closely related to Sauria than to Araeoscelidia (Laurin and Gauthier 2000).

Early or basal Permian neodiaspids were lizard-like, but already include specialised forms for swimming (Claudiosaurus) and gliding (Coelurosauravidae), as well as more conventional lizard-like forms (Youngina etc.). Before the end of the Permian, the neodiapsids give rise to the main branches of the diapsid evolutionary tree, the lepidosaurs and archosaurs.

Classification

The clade Neodiapsida is defined by a number of details in skull and skeleton, for which see Laurin and Gauthier 2000. The cladogram presented here illustrates the "family tree" of reptiles, and follows a simplified version of the relationships found by M.S. Lee, in 2013.[1] All genetic studies have supported the hypothesis that turtles are diapsid reptiles; some have placed turtles within archosauriformes,[1][2][3][4][5][6] though a few have recovered turtles as lepidosauriformes instead.[7] The cladogram below used a combination of genetic (molecular) and fossil (morphological) data to obtain its results.[1]

Diapsida

Araeoscelidia


Neodiapsida

Claudiosaurus




Younginiformes



Lepidosauromorpha

Kuehneosauridae


Lepidosauria

Rhynchocephalia (tuatara and their extinct relatives)



Squamata (lizards and snakes)




Archosauromorpha


Choristodera




Prolacertiformes





Trilophosaurus



Rhynchosauria




Archosauriformes (crocodiles, birds, and their extinct relatives)





 Pantestudines 

Eosauropterygia




Placodontia




Sinosaurosphargis




Odontochelys


Testudinata

Proganochelys



Testudines (turtles)












References

  1. 1.0 1.1 1.2 Lee, M. S. Y. (2013). "Turtle origins: Insights from phylogenetic retrofitting and molecular scaffolds". Journal of Evolutionary Biology 26 (12): 2729. doi:10.1111/jeb.12268.
  2. Mannen & Li 1999
  3. Zardoya & Meyer 1998
  4. Iwabe et al. 2004
  5. Roos, Aggarwal & Janke 2007
  6. Katsu et al. 2010
  7. Lyson et al. 2012

External links