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]
^Glienke, S. (2012). "A new "microsaur" (Amphibia; Lepospondyli) from the Rotliegend of the Saar–Palatinate region (Carboniferous/Permian transition; West Germany)". Paläontologische Zeitschrift. 86 (3): 297–311. Bibcode:2012PalZ...86..297G. doi:10.1007/s12542-012-0130-8. S2CID140699792.
^ abMann, A.; Pardo, J. D.; Maddin, H. C. (2019). "Infernovenator steenae, a new serpentine recumbirostran from the 'Mazon Creek' Lagerstätte further clarifies lysorophian origins". Zoological Journal of the Linnean Society. 187 (2): 506–517. doi:10.1093/zoolinnean/zlz026.
^Anderson, J.S. (2007). "Incorporating ontogeny into the matrix: A phylogenetic evaluation of developmental evidence for the origin of modern Amphibians". In Anderson, J.S.; Sues, H.-D. (eds.). Major Transitions in Vertebrate Evolution. Bloomington and Indianapolis: Indiana University Press. pp. 182–227.
^Huttenlocker, A. K.; Pardo, J. D.; Small, B. J.; Anderson, J. S. (2013). "Cranial morphology of recumbirostrans (Lepospondyli) from the Permian of Kansas and Nebraska, and early morphological evolution inferred by micro-computed tomography". Journal of Vertebrate Paleontology 33 (3): 540.
^Jason D. Pardo, Matt Szostakiwskyj and Jason S. Anderson (2015). "Phylogenetic relationships of recumbirostran 'lepospondyls' inferred from neurocranial morphology". Society of Vertebrate Paleontology 75th Annual Meeting Program & Abstracts: 191.