Ankylopoda

For the extinct group of mammals, see Ancylopoda. For the group of dinosaurs, see Ankylosauria.

Ankylopods Temporal range: Earliest Triassic - Holocene 252–0 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Proganochelys quenstedti
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Sauria
Clade:	Ankylopoda Lyson et al., 2012
Extant subclades
Pantestudines Lepidosauromorpha

Ankylopoda was a proposed clade that hypothetically contains turtles and lepidosaurs (tuatara, lizards and snakes) and their fossil relatives. This clade was historically supported based on microRNA analysis^[1] as well as some cladistic analyses.^[2] However, it was strongly contradicted by molecular evidence which supports Archelosauria (the grouping of turtles and archosaurs),^[3] and other recent cladistic analyses have supported Archelosauria over Ankylopoda.^[4]

Classification

The cladogram below follows the most likely result found by another analysis of turtle relationships, this one using only fossil evidence, published by Rainer Schoch and Hans-Dieter Sues in 2015. This study found Eunotosaurus to be an actual early stem-turtle, though other versions of the analysis found weak support for it as a parareptile.^[5]

Sauria	Archosauromorpha Ankylopoda/Lepidosauromorpha †Kuehneosauridae Lepidosauria Squamata Rhynchocephalia Pantestudines? †Sauropterygia †Eosauropterygia †Sinosaurosphargis †Placodontia †Eunotosaurus †Pappochelys †Odontochelys Testudinata †Proganochelys Testudines

See also

• Archelosauria, an alternative clade that places turtles as sister taxon to archosaurs.

References

1. Lyson, T.R.; Sperling, E.A.; Heimberg, A.M.; Gauthier, J.A.; King, B.L.; Peterson, K.J. (2012). "MicroRNAs support a turtle + lizard clade". Biol. Lett. 8 (1): 104–107. doi:10.1098/rsbl.2011.0477. PMC 3259949. PMID 21775315.
2. Schoch, R. R.; Sues, H.-D. (2015). "A Middle Triassic stem-turtle and the evolution of the turtle body plan". Nature. 523 (7562): 584–7. doi:10.1038/nature14472. PMID 26106865.
3. Joyce, Walter G.; Anquetin, Jérémy; Cadena, Edwin-Alberto; Claude, Julien; Danilov, Igor G.; Evers, Serjoscha W.; Ferreira, Gabriel S.; Gentry, Andrew D.; Georgalis, Georgios L.; Lyson, Tyler R.; Pérez-García, Adán (2021-02-09). "A nomenclature for fossil and living turtles using phylogenetically defined clade names". Swiss Journal of Palaeontology. 140 (1): 5. doi:10.1186/s13358-020-00211-x. hdl:11336/155192. ISSN 1664-2384.
4. Simões, Tiago R.; Kammerer, Christian F.; Caldwell, Michael W.; Pierce, Stephanie E. (2022-08-19). "Successive climate crises in the deep past drove the early evolution and radiation of reptiles". Science Advances. 8 (33). doi:10.1126/sciadv.abq1898. ISSN 2375-2548. PMC 9390993. PMID 35984885.
5. Schoch, Rainer R.; Sues, Hans-Dieter (24 June 2015). "A Middle Triassic stem-turtle and the evolution of the turtle body plan" (PDF). Nature. 523 (7562): 584–587. doi:10.1038/nature14472. PMID 26106865.