Milleropsis (Gow 1972) revisited in 2025

Jenkins et al 2025
used µCT scanning techniques to recover more details on a Milleropsis skull first hand drawn in pen and ink by Gow 1972 (Figs 1, 2).

With this new data Milleropsis was rescored
in the large reptile tree (LRT, 2330 taxa). 20 changes were put in place, chiefly around the once missing, now recovered, premaxilla (Fig 1). The rescoring did not move Milleropsis from its place prior to basal diapsids (e.g. Petrolacosaurus) in the archosauromorph half of the reptile subset of the LRT (subset Fig 3).

Unfortunately
due to taxon exclusion and adherence to tradition the Jenkins et al assessment of Milleropsis is out-of-date. Instead of testing prior studies, the eight co-authors reported, “The exclusively South African Millerettidae are generally considered to be the earliest diverging members of Parareptilia.”

“Generally considered” = opinion, tradition. That’s not good science.

Unfortunately, academics are encouraged not to test additional taxa. Instead academics are encouraged to cite invalid clades, like ‘Parareptilia.”

No phylogenetic analysis was undertaken and no cladogram was presented.

Historically, as reported by Jenkins et al,
“Millerettidae are a group of superficially lizard-like Permian stem reptiles originally hypothesized as relevant to the ancestry of the reptile crown group, and particularly to
lepidosaurs and archosaurs.”

By contrast, in the LRT Milleretta is not related to Milleropsis and Millerosaurus. None have a close relationship to lepidosaurs or archosaurs, which are not related to each other.

“Since the advent of cladistics, millerettids have typically been considered to be more
distant relatives of crown reptiles as the earliest-diverging parareptiles and therefore outside of ‘Eureptilia’. Despite this cladistic consensus, some conspicuous features of millerettid anatomy invite reconsideration of their relationships.”

All this has been out-of-date since the above taxa entered the LRT in 2012.

Jenkins et al confessed this ongoing problem in their Introduction.
“Understanding the origins of modern reptiles has been confounded by patterns of available fossiliferous rock in which to sample terrestrial vertebrates in the late Palaeozoic, and an approximately 60-million-year-long period with several expansive ghost lineages between the earliest diapsid Petrolacosaurus kansensis, and the appearance of the reptile crown group Sauria under prevailing phylogenetic paradigms.”

By contrast, the LRT recovered the origin of the clade Reptilia in 2011 with this announcement of the basal dichotomy and this announcement in 2016 of Silvanerpeton nesting as the last common ancestor of all members of the Reptilia.

“Modern cladistic analyses have reinforced the concept of extensive ghost lineages for the reptile crown stretching from the latest Carboniferous to the late Permian, organizing reptile clades into two groups, Eureptilia and Parareptilia.”

Not so modern due to taxon exclusion. The LRT minimizes taxon exclusion. Reptiles originated in the Early Carboniferous, splitting the Lepidosauromorpha from the Archosauromorpha right after Silvanerpeton.

PS If you take a test at a university, make sure you repeat what they taught you.

References
Jenkins et al  (7 co-authors) 2025. Cranial osteology and neuroanatomy of the late Permian reptile Milleropsis pricei and implications for early reptile evolution. R. Soc. Open Sci. 12: 241298.https://doi.org/10.1098/rsos.241298

wiki/Milleropsis

Source: https://pterosaurheresies.wordpress.com/2025/01/12/milleropsis-gow-1972-revisited-in-2025/