‘The phylogenetic origin of turtles’ (Jenkins et al 2026) omits relevant taxa

Saturday, May 30, 2026 8:17

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From the ‘In brief’ preface:
“Jenkins et al. present the largest morphological dataset for early reptile phylogeny,”

Sadly, far from the largest dataset. Actually the large reptile tree (LRT, 2340 taxa) is larger. Much larger. The LRT informs us that the Jenkins et al study omitted several relevant taxa.
When you write your own manuscript, try to avoid superlatives that are neither superlative nor correct.

“recovering turtles as sisters to archosaurs“

This is wrong. Archosaurs are far from turtles in the LRT (subset Fig 1).
Find this out for yourself with a similar taxon list.

Genetic studies too often recover untenable results not recovered by trait analysis that includes fossils. So ignore deep time gene studies. They are somehow corrupt.

“and rejecting Eunotosaurus as a stem turtle. Instead, Eunotosaurus is a millerettid stem reptile whose turtle-like features arose through convergence, possibly driven by shared fossorial ecology, thus reframing the origins of the turtle shell.”

This is correct! Congratulations are in order.
And… you heard it here first back in 2011, (Fig 2) without a professor co-author or µCT scans.

Figure 1. Subset of the LRT focusing on turtles and their ancestors back in 2021. Check the LRT for updates.

From the phylogenetic results section
“Phylogenetic analyses were conducted using a modified and substantially expanded version of the dataset of Jenkins et al., designed to test all major hypotheses of turtle origins by incorporating all fossil reptile groups implicated in turtle origins together with the anatomical observations and character evidence originally advanced in support of each of these hypotheses.”

Taxon exclusion hobbled all three studies. That’s why the LRT is here.
Check the LRT before making superlative claims – or use it to save time.

And again avoid superlatives like “designed to test ALL major hypotheses”
– especially when your study doesn’t test all major hypotheses..

Figure 2. Eunotosaurus and its sister taxa, Acleistorhinus and Milleretta RC14 from 2011

Don’t confuse ‘earliest known’ with ‘most primitive after analysis’.
Jenkins et al wrote, “Until recently, the earliest known unambiguous stem turtle was Proganochelys quenstedtii from the Late Triassic of Germany, which already shows an anapsid skull and the fully formed carapace and plastron46 characteristic of turtles.”

Test. Don’t assume. This time the anapsid skull really is a primitive condition.
Don’t twist things around from anapsid to diapsid back to anapsid in the evolutionary journey of turtles.
Add taxa. That’s the only way to discover overlooked and valid interrelationships.
Also check ResearchGate. so you don’t claim to be the largest or first when your study is neither superlative.
Also check Google where ‘What is Eunotosaurus?’ from 2011 appears on page one in Google results in 2026.

Special thanks
to reader Sean M for bringing this study to my attention.

References
Jenkins et al in press 2026. The phylogenetic origin of turtles, Current Biology, https://doi.org/10.1016/j.cub.2026.04.070
Jenkins, X.A., et al 2025. Evolutionary assembly of crown reptile anatomy clarified by late Paleozoic relatives of Neodiapsida. Peer Community J. 5.
Jenkins, X.A et al 2026. The origin of the tympanic fossa in reptiles revealed by a late Permian neodiapsid. Palaeontology 69. https://doi.org/10.1111/pala.70041.
Peters D 2018. The dual origin of turtles from pareiasaurs. ResearchGate.net
DOI:10.13140/RG.2.2.23288.29444