Parareptilia
Skeletal reconstruction of Bradysaurus
Worldwide
Para reptiles are an extinct group of reptiles that arose from an early diversification of higher terrestrial vertebrates in the Carboniferous, however, is assigned only from the Early Permian fossil record through and survived with the Procolophoniden until the end of the Triassic.
Tribal History Para reptiles are defined as the least exclusive community of descent, the Milleretta rubidgei and Procolophon trigoniceps belong, but not Captorhinus aguti (see Müller and Tsuji, 2009). The sister group of the para reptiles represent the Eureptilien, which also include the extant groups of the scaled reptiles, crocodiles and birds. The position of turtles ( Testudinata ) in the classification of reptiles is uncertain.
Features
Diagnostic features of the Para reptiles are (according to Müller and Tsuji 2007; Tsuji and Müller 2009), among others, the absence of contact of the lacrimal to the nostril, the lack of a canine, a single centrally located indentation at the posterior margin of the skull roof, the lack of a Supraglenoid - opening, the lack of a Subtemporalfortsatzes on Jugale, the fixed contact of the prefrontal to the palatine, a ventral side extended Quadratojugale, and the position of the temporomandibular joint at the level of the occiput or something behind it.
The Para reptiles are very diverse and include both aquatic and fully terrestrial Mesosaurier groups such as the massive built Pareiasaurier and the lizard-like Bolosauriden, Milerettiden, " Nycteroleteriden " and Procolophonoideen. While some groups like the Millerettiden probably insectivores were (larger " Nycteroleteriden " as Macroleter, probably even meat -eaters ) and the Mesosaurier fed on fish and aquatic arthropods, Bolosauriden, Procolophonoideen and Pareiasaurier be interpreted because of their dentures than herbivores (see Benton 2005 pp. 113-118 ).
Relationships
The following cladogram shows the phylogenetic relationships of the para reptiles according to Tsuji and Müller ( 2009) represents the breakdown of Eureptilien follows Laurin and Reisz (1995 ) (see also Benton, 2005).
Synapsida (including mammals)
Mesosauridae
Millerettidae
Lanthanosuchoidea
Nyctiphruretus
Procolophonoidea
Pareiasauria
" Nycteroleteridae "
Captorhinidae
Paleothyris
Diapsida ( including today's reptiles and groups of birds )
The group of reptiles ( Reptilia ) includes here as defined by Modesto and Anderson ( 2004), the present-day reptile groups and all animals that are more closely related to them than to the mammals. Synonym to Reptilia also Sauropsida is used as the group name. The position of Eunotosaurus addition to Milleretidae is uncertain osteological findings suggest a closer relationship with the turtles back.
Core group of turtles?
The significantly different compared to other modern reptiles groups anatomy of turtles, including the anapside skull, ie a skull with no temporal openings were, and still are some paleontologists reason to believe that these special characteristics are due to an early separation of the lineages of turtles and the living today Diapsiden and that it was at the Para reptiles to the nearest fossil relatives of turtles. Possible Para Reptile sister groups of turtles were once the Procolophoniden ( Laurin and Reisz, 1995 ) and the Pareiasaurier ( see, eg, Lee 1997) and recently again Eunotosaurus ( Lyson et al., 2010).
For the corresponding clade (Para reptiles including turtles) was in the meantime the name Anapsida in use ( Modesto, 1999).
That osteological similarities that point to a relationship of turtles with the parameters reptiles, actually represent homologous features, is considered doubtful (see Rieppel and Reisz 1999; Rieppel 2000) and especially molecular biological findings point to a position of turtles within the Diapsiden ( Zardoya and Meyer 1998, Cao et al 2000). Moreover, there are hardly knochenhistologische matches between the skin bony plates ( osteoderms ) of Pareiasaurier and tortoise shells, which histologically resemble rather the dermal bones of the Diapsiden ( Scheyer and Sander 2009).