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| Breagnathair elgolensis Benson, Walsh, Griffiths, Kulik, Botha, Fernandez, Head & Evans, 2025 Life reconstruction: Mick Ellison (AMNH) |
Abstract
Squamates (lizards and snakes) comprise almost 12,000 living species, with wide ecological diversity and a crown group that originated around 190 million years ago. Conflict between morphology and molecular phylogenies indicates a complex pattern of anatomical transformations during early squamate evolution, which remains poorly understood owing to the scarcity of early fossil taxa. Here we present Breugnathair elgolensis gen. et sp. nov., based on a new skeleton from the Middle Jurassic epoch (167 million years ago) of Scotland, which is among the oldest relatively complete fossil squamates. Breugnathair is placed in a new family, Parviraptoridae, an enigmatic group with potential importance for snake origins, that was previously known from very incomplete remains. It displays a mosaic of anatomical traits that is not present in living groups, with head and body proportions similar to varanids (monitor lizards) and snake-like features of the teeth and jaws, alongside primitive traits shared with early-diverging groups such as gekkotans. Phylogenetic analyses of multiple datasets return conflicting results, with parviraptorids either as early toxicoferans (and potentially stem snakes) or as stem squamates that convergently evolved snake-like dental and mandibular traits related to feeding. These findings indicate high levels of homoplasy and experimentation during the initial radiation of squamates and highlight the potential importance of convergent morphological transformations during deep evolutionary divergences.
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| Reconstruction of Breagnathair elgolensis from NMS G.2023.7.1. a, Life reconstruction of Breagnathair elgolensis based on measured proportions of NMS G.2023.7.1. b, Digital render of the bones as originally preserved in NMS G.2023.7.1, using information from the pilot scan (Supplementary Data 1 and 2). c–f, Digital renders of cervical vertebra (CEb in Extended Data Fig. 5) in left lateral (c), ventral (d), anterior (e) and posterior (f) views. g–i, Caudal vertebra (CAa in Extended Data Fig. 5) in left lateral (g), ventral (h) and anterior (i) views. Scale bars: 50 mm (b), 2 mm (c–i). Life reconstruction reproduced with permission from Mick Ellison (American Museum of Natural History). |
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| Breagnathair elgolensis Life reconstruction: Mick Ellison (American Museum of Natural History). |
Pan-Squamata Gauthier & de Queiroz, 2020
Parviraptoridae new family
Included taxa. Parviraptor estesi (type genus), Diablophis gilmorei, Portugalophis lignites and Breugnathair elgolensis gen. et sp. nov., as well as the holotype and at least some specimens referred to the nomen dubium Eophis underwoodi, from the Middle Jurassic of Kirtlington. ...
Breugnathair elgolensis gen. et sp. nov.
Etymology. breug-nathair (brjiag Nahɪrj; adapted from Scottish Gaelic): false snake; specific name comes from the locality of discovery, north of the village of Elgol on the Strathaird Peninsula of the Isle of Skye.
Holotype. NMS (National Museums of Scotland, Edinburgh, UK) G.2023.7.1, a disarticulated partial skeleton from the Middle Jurassic (Bathonian, 166 Ma) Kilmaluag Formation of the Elgol Coast SSSI14, collected in 2015 under permit from NatureScot, with permission from the landowner John Muir Trust.
Diagnosis. Parviraptorid that differs from Early Cretaceous Parviraptor estesi in having proportionally narrower parietals that bear a nuchal shelf and lack a deep ventral concavity between the base of the postparietal process and the base of the supratemporal process; differs from Late Jurassic Portugalophis lignites by having shorter interdental ridges and more sharply recurved tooth crowns; and differs from Late Jurassic Diablophis gilmorei in the less bulbous morphology of tooth bases, and substantially more recurved crowns. ...
Roger B. J. Benson, Stig A. Walsh, Elizabeth F. Griffiths, Zoe T. Kulik, Jennifer Botha, Vincent Fernandez, Jason J. Head and Susan E. Evans. 2025. Mosaic Anatomy in an early Fossil Squamate. Nature. DOI: doi.org/10.1038/s41586-025-09566-y [01 October 2025]
