Chroniosuchia

Chroniosuchus, a Chroniosuchier from the Upper Permian of Russia.

  • European Russia, China, South Germany

Chroniosuchier are an extinct group of Reptiliomorpha whose members are characterized by a set of inter- connected in an articulated skin bony plates ( osteoderms ) along the body line of the back. Except for isolated occurrences from the Upper Permian of China and the triad of copper cell, Baden- Württemberg, Chroniosuchier are occupied exclusively from Permian to Triassic continental sedimentary rocks of the European part of Russia by the fossil record.

Skeletal features

As Seymouriamorpha and Diadectomorpha but in contrast to adult Embolomeri Chroniosuchier the neural arch was for the vertebrae fused to the Pleurocentrun. Their shape was concave on both sides ( amphicoel ), so that between two Pleurocentren each a spherical to ellipsoidal intercentrum einpasste (see Vyushkov 1957, Golubev 2000).

Osteoderms of the back series that stretched from neck to tail front, sat with their Ventralfortsätzen either mobility on the spinous processes of the vertebrae to or were merged with them. The assignment Osteoderm / vortex was there strictly 1:1. On the complex articulation of two adjacent osteoderms forward and backward pointing projections contributed to the plate bottom, the overlapped each other and aligned to the vortex zygapophyses. The osteoderms of Chroniosuchidae differ from those of the second sub-group, the Bystrowianidae, including by the presence of additional paired joint surfaces. The Bystrowianiden and some Chroniosuchiden the narrow osteoderms covered only the area of the body axis from, demhingegen the osteoderms were wide with Chroniosuchus, Chroniosaurus and Jarilinus and formed segmented armor (see Golubev 1998-2000, Novikov et al., 2000).

An unusual feature of the Chroniosuchiden Skull is the presence of large situated in front of the eye opening cranial window ( Antorbitalforamen ), later such openings occur on convergent in archosaurs. Chroniosuchiden could obviously cheek and upper jaw move relative to the skull roof and with this form of Schädelkinese the mouth laterally expand ( Golubev 2000).

Way of life

Because of their skull morphology, frequent evidence from lake sediments and their association with fish fossils Chroniosuchiden be construed as crocodile -like aquatic predators ( Golubev 2000) - However, the findings contradict knochenhistologische (see Laurin et al 2004. ); However, Bystrowianiden come into the Russian fossil sites mostly related to vertebrates, whose way of life was not bound to the water.

Relationships

Chroniosuchier were first reported by Vyushkov ( 1957a ) as a separate group ( family Chroniosuchidae ) within the Batrachosaurier, in the same year, Vyushkov ( 1957b ) the family Bystrowianidae on, without, however, to draw as next of kin of Chroniosuchiden into consideration. Tatarinov (1972 ) ranked both groups to the Seymouriamorpha and created for the Chroniosuchiden own subordination ( Chroniosuchi ( d) a). In their revision added Ivakhnenko and Tverdochlebova (1980 ) the Bystrowianiden the Chroniosuchiern as the second part group, and then justified the hypothesis that Chroniosuchier are the closest relatives of Anthracosauria. The group of Chroniosuchier and Anthracosaurier received the designation Anthracosauromorpha, which was used in most subsequent publications.

Inside systematics

  • Chroniosuchidae Vyushkov, 1957
  • Chroniosuchus Vyushkov, 1957
  • Chroniosaurus Tverdochlebova, 1972
  • Jarilinus Golubev, 1998
  • Uralerpeton Golubev, 1998
  • Suchonica Golubev, 1999
  • Madygenerpeton Schoch, Voigt & book joke, 2010
  • Bystrowianidae Vyushkov, 1957
  • Bystrowiana Vyushkov, 1957
  • Axitectum Novikov & Shishkin, 1992
  • Dromotectum Novikov & Shishkin, 1996
  • Synesuchus Novikov & Shishkin, 1996
  • Bystrowiella joke man, Schoch & Maisch, 2008
Mya (unit)
188928
de