Millerosauria

Millerosauria Temporal range: Middle to Late Permian, 265.8–251 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Reconstructed skull of Milleretta
Fossil of Eunotosaurus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Subclass:	†Parareptilia
Order:	†Millerosauria Watson, 1957
Families
†Millerettidae †Eunotosauridae?
Synonyms
Millerosauroidea Romer, 1966

Millerosauria is a proposed extinct order of early reptiles that contains the families Millerettidae and Eunotosauridae. It was named in 1957 by Watson and represents a group of reptiles that were thought to be ancestral to Eosuchia (a now-defunct clade roughly corresponding to the non-saurian Neodiapsida) and modern reptiles.^[1] Many cladistic studies have interpreted members of the Millerosauria as an early-diverging group of 'parareptiles', but some phylogenetic analyses have demonstrated that 'Parareptilia' represents a group of unrelated early reptiles and is therefore polyphyletic.^[2][3] In 2025, Jenkins et al. recovered the subgroup Millerettidae close to Neodiapsida as the earliest-diverging group in the clade Parapleurota.^[4]

Eunotosaurus has been recovered as a stem-turtle in some cladistic studies.^[5]

References

1. "On Millerosaurus and the early history of the sauropsid reptiles". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 240 (673): 325–398. 1957-03-28. doi:10.1098/rstb.1957.0003. ISSN 2054-0280.
2. 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) eabq1898. doi:10.1126/sciadv.abq1898. PMC 9390993. PMID 35984885.
3. Jenkins, Kelsey M.; Foster, William; Napoli, James G.; Meyer, Dalton L.; Bever, Gabriel S.; Bhullar, Bhart-Anjan S. "Cranial anatomy and phylogenetic affinities of Bolosaurus major, with new information on the unique bolosaurid feeding apparatus and evolution of the impedance-matching ear". The Anatomical Record. doi:10.1002/ar.25546. ISSN 1932-8494.
4. Jenkins, Xavier A; Benson, Roger BJ; Ford, David P; Browning, Claire; Fernandez, Vincent; Dollman, Kathleen; Gomes, Timothy; Griffiths, Elizabeth; Choiniere, Jonah N; Peecook, Brandon R (2025-08-28). "Evolutionary assembly of crown reptile anatomy clarified by late Paleozoic relatives of Neodiapsida". Peer Community Journal. 5. e89. doi:10.24072/pcjournal.620. ISSN 2804-3871.
5. Schoch, Rainer R.; Sues, Hans-Dieter (2015-07-24). "A Middle Triassic stem-turtle and the evolution of the turtle body plan". Nature. 523 (7562): 584–587. doi:10.1038/nature14472. ISSN 0028-0836.

• "Millerosauria". Paleobiology Database. Retrieved 13 August 2013.