New paper on Ardeosaurus and Eichstaettisaurus as geckos

Ardeosaurus and Eichstaettisaurus (Fig. 1) have been traditional enigmas in paleo studies. Here is some progress from Simões et al. 2016, who nest these two with geckos, as they were initially placed. The large reptile tree nests these two at the base of snakes, as sisters to the gecko clade. So very close!
Eichstattisaurus and Ardeosaurus.

Figure 1. Eichstattisaurus and Ardeosaurus. Two Jurassic lizards in the lineage of snakes – but very close to geckos.

From the Simões abstract:
“Late Jurassic lizards from Solnhofen, Germany, include some of the oldest known articulated lizard specimens, sometimes including soft tissue preservation. These specimens are thus very important to our understanding of early squamate morphology and taxonomy, and also provide valuable information on squamate phylogeny. Eichstaettisaurus schroederi and Ardeosaurus digitatellus are two of the best-preserved species from that locality, the former being represented by one of the most complete lizard specimen known anywhere in the world from the Jurassic. Despite their relevance to broad questions in squamate evolution, their morphology has never been described in detail, and their systematic placement has been under debate for decades. Here, we provide the first detailed morphological description, species-level phylogeny, and functional morphological evaluation of E. schroederi and A. digitatellus. We corroborate their initial placement as geckoes (stem gekkotans, more specifically), and illustrate a number of climbing adaptations that indicate the early evolution of scansoriality in gekkonomorph lizards.”

A PDF has been requested.
We’ll see if they included any basal snakes in their analysis.
This just in. The PDF arrived
The Simoes et al. cladogram nests snakes within skinks, derived from amphisbaenids. I don’t see Tetrapodophis or other pre-snakes in their cladogram.
Broili F 1938. Ein neuer fund von ?Ardeosaurus H. von Meyer. S.-B. bayer. Akad. Wiss. München, math.-naturw. Abt. 97-114.
Conrad JL and Daza JD 2015. Naming and rediagnosing the Cretaceous gekkonomorph (Reptilia, Squamata) from Öösh (Övörkhangai, Mongolia). Journal of Vertebrate Paleontology 35:5, e980891
Conrad JL and Norell MA 2006. High-resolution x-ray computed tomography of an Early Cretaceous gekkonomorph (Squamata) from Öosh ( €Ov€orkhangai; Mongolia). Historical Biology 18:405–431.
Daza JD, Bauer AM and Snively E 2013. Gobekko cretacicus (Reptilia: Squamata) and its bearing on the interpretation of gekkotan affinities. Zoological Journal of the Linnean Society 167:430–448.ischen Akademie der Wissenschaften, München 1938: 97–114.
Evans SE, Raia P and Barbera C 2004. New lizards and rhynchocephalians from the Lower Cretaceous of southern Italy. Acta Palaeontologica Polonica 49:393-408.
Hoffstetter R 1953. Les Sauriens anté−crétacés. Bulletin de la Museum Nationale d’Histoire Naturelle 25: 345–352.
Kuhn O 1958. Ein neuer lacertilier aus dem fränkischen Lithographie−schiefer. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 1958: 437–440.
Mateer NJ 1982. Osteology of the Jurassic Lizard Ardeosaurus brevipes (Meyer). Palaeontology 25(3):461-469. online pdf
Meyer H von 1860. Zur Fauna der Vorwelt. Reptilien aus dem lithographischen Schiefer des Jura in Deutschland mit Franchreich. Frankfurt-am-Main.
Simões TR, Caldwell MW, Nydam RL and Jiménez-Huidobro P 2016. Osteology, phylogeny, and functional morphology of two Jurassic lizard species and the early evolution of scansoriality in geckoes. Zoological Journal of the Linnean Society (advance online publication) DOI: 10.1111/zoj.12487

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