Recumbirostra
Extinct clade of tetrapods
From Wikipedia, the free encyclopedia
Recumbirostra is a clade of tetrapods which lived during the Carboniferous and Permian periods. They are thought to have had a fossorial (burrowing) lifestyle and the group includes both short-bodied and long-bodied snake-like forms.[1][2] At least one species, the long-bodied molgophid Nagini mazonense, lost its forelimbs entirely.[3] Recumbirostra includes the families Pantylidae, Gymnarthridae, Ostodolepidae, Rhynchonkidae and Brachystelechidae, with additional families such as Microbrachidae and Molgophidae being included by some authors.[4][5] Brachystelechidae and Molgophidae have also been grouped together in the suggested clade Chthonosauria.[6]
| Recumbirostra Temporal range: Late Carboniferous - Early Permian, | |
|---|---|
| |
| Life restoration of the rhynchonkid Rhynchonkos | |
 | |
| Life restoration of Batropetes, a brachystelechid | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Reptiliomorpha |
| Clade: | †Recumbirostra Anderson, 2007 |
| Subgroups | |
|
see text | |
Recumbirostra was erected as a clade in 2007 to include many of the taxa traditionally grouped in "Microsauria", which has since been shown to be a paraphyletic or polyphyletic grouping.[7][8][9] Like other "microsaurs", the recumbirostrans have traditionally been considered to be members of the subclass Lepospondyli; however, many phylogenetic analyses conducted since the 2010s have recovered recumbirostrans as basal sauropsid (reptilian) amniotes instead.[10][7][5][3][11] However, the placement of recumbirostrans as reptiles has been challenged by other authors, who have recovered them as stem-amniotes instead, and contended that the shared characters between recumbirostrans and reptiles are convergent,[12] or the result of incorrect character encoding.[13] Not all phylogenetic analyses recognize Recumbirostra as a valid grouping. An alternative clade called Tuditanomorpha is occasionally supported and includes many of the same taxa.[14] Furthermore, the taxa that are often considered to be recumbirostrans have been found among amphibians (and not as a distinct clade) in some analyses.[15]
Classification
Taxonomy
Phylogeny
Below is a cladogram showing the phylogenetic relationships of recumbirostrans from Glienke (2012):[4]
| Recumbirostra | |
Gallery
Skeleton of Joermungandr bolti, showing preserved remains of scales
Skeleton of the brachystelechid Batropetes
Skull of the molgophid Brachydectes
Skull of the ostodolepid Nannaroter
