Late Triassic †Cryptovaranoides microlanius is a squamate, not an archosauromorph

Abstract

†Cryptovaranoides microlanius from the latest Triassic of England was described in 2022 as a crown-clade squamate, of importance as the oldest such modern-type lizard, extending their temporal range downward by 35 Myr. This view was challenged in 2023, and †Cryptovaranoides was reinterpreted as an archosauromorph. These decisions matter because the original view has an impact on our understanding of the early stages of squamate evolution; the revised view removes the species from such a role. The revisers emphasized the need to make careful observations of the fossils and to interpret the morphological data appropriately in terms of relationships; here, we find many errors of observation and interpretation in the work of the revisers, and we correct these with reference to the fossils, both in the rock and in the computed tomography scans we had made for the original description. We show that when the observational errors are corrected and the taxa recoded, every phylogenetic analysis confirms our original conclusion that †Cryptovaranoides is not an archosauromorph, but a lepidosauromorph, a lepidosaur, a pan-squamate and a crown squamate.

Keywords

• phylogenetics
• divergence times
• Squamata
• reptiles
• Triassic
• †Cryptovaranoides