Diadectomorpha

Diadectomorpha
Live reconstruction of Diadectes , a Diadectidae from the early Permian of North America
Temporal occurrence
Upper Carboniferous to Lower Permian
311.3 to 272.5 million years
Locations
Europe North America
Systematics
Chordates (chordata) Vertebrates (vertebrata) Jaw mouths (Gnathostomata) Land vertebrates (Tetrapoda) Reptiliomorpha Diadectomorpha
Scientific name
Diadectomorpha
Watson , 1917

The Diadectomorpha are a group of extinct terrestrial vertebrates that show features of both amphibians and reptiles . They lived in the epochs of the Upper Carboniferous and the early Permian (Cisuralium) on the supercontinent Laurussia .

They include large carnivores such as Limnoscelis , up to two meters long and sometimes aquatic , as well as the first large, herbivorous land vertebrates. Diadectes grew to be ten feet long, had a highly specialized skull with a secondary palate and molar-shaped molars, so that it is believed to feed on hard plants.

Systematics

External system

Originally, the taxon "Cotylosauria" was established as the most original order of reptiles for the Diadectomorpha . Both amphibians and primitive amniotes were assigned to the taxon . In the meantime the "Cotylosauria" have proven to be paraphyletic . The Diadectomorpha are now considered a sister group of the amniotes and are placed with them in the taxon Reptiliomorpha , which is the sister group of the amphibians.

• Land vertebrates (Tetrapoda)
  • Amphibia
  • Reptiliomorpha
    • Amniota ( reptiles , birds , mammals )
    • Diadectomorpha

After examining the occipital region of Limnoscelis and Diadectes , the systematic position of the Diadectomorpha was reassessed. They are said to be the sister group of Synapsida , a taxon that also includes mammals . This means that the Diadectomorpha are amniotes . The unnamed clade formed by the Diadectomorpha and Synapsida is the sister group of the reptiles.

• Land vertebrates (Tetrapoda)
  • Amphibia
  • Amniota
    • Reptiles
    • Unnamed clade
      • Diadectomorpha
      • Synapsida

Limnoscelis paludis from early Permian North America

Diasparactus zenos

Holotype of Orobates pabsti named after Wilhelm Pabst in the Museum der Natur Gotha

Internal system

• Diadectomorpha
  • Limnoscelidae
    • Limnoscelis
    • Limnosceloides
    • Limnoscelops
    • Limnostygis
  • Tseajaiidae
    • Tseajaia
  • Diadectidae
    • Alveusdectes
    • Ambedus
    • Desmatodon
    • Diadectes
    • Diasparactus
    • Orobates
    • Stephanospondylus

literature

• Robert L. Carroll: Paleontology and Evolution of the Vertebrates. Thieme-Verlag, Stuttgart, 1993, ISBN 3-13774-401-6

Web links

Commons : Diadectomorpha  - collection of images, videos and audio files

Individual evidence

1. ^ David S. Berman: Origin and Early Evolution of the Amniote Occiput . Journal of Paleontology, vol. 74, no. 5 (Sep., 2000), pp. 938-956 abstract
2. ↑ Diadectomorpha - Diadectids and relative Mikko's Phylogeny Archive ( Memento of the original from August 18, 2005 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.