Lepidosauromorpha

Lepidosauromorpha
Bridge lizard ( Sphenodon )
Temporal occurrence
Triassic to Holocene
245.9 to 0 million years
Locations
Worldwide
Systematics
Jaw mouths (Gnathostomata) Land vertebrates (Tetrapoda) Amniotes (Amniota) Sauropsida Diapsida Lepidosauromorpha
Scientific name
Lepidosauromorpha
Benton , 1983

The Lepidosauromorpha are a taxon of the reptiles or Sauropsiden , which includes the Lepidosauria ( bridge lizards and scaled reptiles ) as well as all diapsid reptiles that are more closely related to the Lepidosauria than to the Archosauria ( crocodiles and birds ). This taxon is primarily used in paleontology as all subtaxa outside of the lepidosauria are extinct.

features

In contrast to the archosaurs , the lepidosauromorphs maintain the primitive locomotion of the early Tetrapoda through the sideways, winding movement of the spine. Already in the Upper Permian they develop a sternum , which however has a different structure and function than that of the archosaurs and is not homologous with it. The sternum expands the range of motion of the front legs. In addition, they keep the spread-legged position of the extremities and show no tendency to put them under the body, as did the dinosaurs , for example .

Systematics

The Lepidosauromorpha include the scale lizards (Lepidosauria), the representatives of the completely extinct group Sauropterygia , which make up the majority of the Mesozoic marine reptiles, as well as some other representatives from the Mesozoic era. Sister group of the Lepidosauromorpha are the Archosauromorpha . Assuming that the turtles (Testudines) do not represent an independent line of reptile evolution and are to be assigned to either the Lepidosauromorpha or the Archosauromorpha, these two large groups form the reptile crown group .

Brachauchenius , a pliosaur of the order Plesiosauria

Western sand boa
( Eryx jaculus )

• Lepidosauromorpha
  • Sauropterygia †
    • Placodontia †
    • Pachypleurosauria †
    • Nothosauria †
    • Plesiosauria †
  • Lepidosauriformes
    • Eolacertilia †
      • Icarosaurus †
      • Kuehneosaurus †
    • Lepidosauria
      • Sphenodontia (with the recent bridge lizards)
      • Scale reptiles (Squamata)
        • Iguana (Iguania)
        • Geckos (gekkota)
        • Scincomorpha (Scincoidea)
        • Sneaky (Anguimorpha)
        • Snakes (serpentes)
        • Double creeping (Amphisbaenia)
        • Snake creeps (Dibamidae)

literature

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

Web links

• Lepidosauromorpha on Palaeos - Life Through Deep Time (English)
• Lepidosauromorpha at the Tree of Life Web Project (English)
• Lepidosauromorpha. Sheet in the Paleobiology Database (English)