Gekkota (geckos and pygopodids) is a clade thought to have originated in the Early Cretaceous and that today exhibits one of the most remarkable scansorial capabilities among lizards. Little information is available regarding the origin of scansoriality, which subsequently became widespread and diverse in terms of ecomorphology in this clade. An undescribed amber fossil (MCZ R–190835) from mid-Cretaceous outcrops of the north of Myanmar dated at 99 Ma, previously assigned to stem Gekkota, preserves carpal, metacarpal and phalangeal bones, as well as supplementary climbing structures, such as adhesive pads and paraphalangeal elements. This fossil documents the presence of highly specialized adaptive structures. Here, we analyze in detail the manus of the putative stem Gekkota. We use morphological comparisons in the context of extant squamates, to produce a detailed descriptive analysis and a linear discriminant analysis (LDA) based on 32 skeletal variables of the manus. The comparative sample includes members of 15 extant squamate families (Agamidae, Dactyloidae, Iguanidae, Leiosauridae, Liolaemidae, Polychrotidae, Tropiduridae, Diplodactylidae, Eublepharidae, Gekkonidae, Phyllodactylidae, Sphaerodactylidae, Gymnophthalmidae, Teiidae, and Scincidae). Although the fossil manus is qualitatively more similar to that of members of Gekkota, the LDA analysis places it in a morphozone shared by Gekkota and Scincomorpha. This result is particularly interesting, given that despite the presence of paraphalangeal structures had only been reported in extant geckos of the families Gekkonidae and Phyllodactylidae, the usage of an adhesive subdigital system to climb originated independently in Gekkota, Scincidae, and Dactyloidae.
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Comparative cranial osteology of European gekkotans (Reptilia, Squamata)
Comparative osteology of European lizards, and of European geckos in particular, is poorly known, resulting in problems when trying to determine to species isolated bones found as fossils or as remains of prey in scats or pellets. In order to partly solve this issue, we here present a detailed comparative analysis of the cranial bones of the four most broadly distributed species of European gekkotans: Euleptes europaea, Hemidactylus turcicus, Mediodactylus kotschyi and Tarentola mauritanica. The skulls of these species display both a set of features that are typical for geckos in general and unique features that can be employed to identify isolated bones of all considered species. Diagnostic differences are found in almost every bone (except the squamosal, epipterygoid and stapes), leading to the creation of a detailed diagnostic key. The dentition also displays some interspecific differences, even though all four species share a similar general tooth morphology, with pleurodont teeth provided with two parallel cutting edges separated by a groove-like space. Such a dentition is consistent with an arthropod-based diet.
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- Award ID(s):
- 1657656
- NSF-PAR ID:
- 10092688
- Date Published:
- Journal Name:
- Zoological journal of the Linnean Society
- Volume:
- 184
- Issue:
- 3
- ISSN:
- 0024-4082
- Page Range / eLocation ID:
- 857 - 895
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/doi.org/10.1093/zoolinnean/zlx104
