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Squamata

About: Squamata is a research topic. Over the lifetime, 1096 publications have been published within this topic receiving 23909 citations. The topic is also known as: scaled reptile.


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Journal ArticleDOI
TL;DR: A new large-scale phylogeny of squamate reptiles is presented that includes new, resurrected, and modified subfamilies within gymnophthalmid and scincid lizards, and boid, colubrid, and lamprophiid snakes.
Abstract: The extant squamates (>9400 known species of lizards and snakes) are one of the most diverse and conspicuous radiations of terrestrial vertebrates, but no studies have attempted to reconstruct a phylogeny for the group with large-scale taxon sampling. Such an estimate is invaluable for comparative evolutionary studies, and to address their classification. Here, we present the first large-scale phylogenetic estimate for Squamata. The estimated phylogeny contains 4161 species, representing all currently recognized families and subfamilies. The analysis is based on up to 12896 base pairs of sequence data per species (average = 2497 bp) from 12 genes, including seven nuclear loci (BDNF, c-mos, NT3, PDC, R35, RAG-1, and RAG-2), and five mitochondrial genes (12S, 16S, cytochrome b, ND2, and ND4). The tree provides important confirmation for recent estimates of higher-level squamate phylogeny based on molecular data (but with more limited taxon sampling), estimates that are very different from previous morphology-based hypotheses. The tree also includes many relationships that differ from previous molecular estimates and many that differ from traditional taxonomy. We present a new large-scale phylogeny of squamate reptiles that should be a valuable resource for future comparative studies. We also present a revised classification of squamates at the family and subfamily level to bring the taxonomy more in line with the new phylogenetic hypothesis. This classification includes new, resurrected, and modified subfamilies within gymnophthalmid and scincid lizards, and boid, colubrid, and lamprophiid snakes.

1,381 citations

01 Jan 1988
TL;DR: Camp, Charles Lewis ; Classification ; Congresses ; NH-Vertebrate Zoology ; Research Associate ; NMNH ; SDR
Abstract: Camp, Charles Lewis ; Classification ; Congresses ; NH-Vertebrate Zoology ; Research Associate ; NMNH ; SDR

709 citations

Book
01 Jan 1995
TL;DR: A zoogeographical analysis based on the combined distribution maps of the various species shows a main division in Amazonia of a western and an eastern fauna, and a southwestern group is also recognised and, although defined by a smaller number of species, a Guianan group.
Abstract: Eighty-nine species of lizards, six of which polytypic (forming a total of 97 taxa), are presently known from Brazilian Amazonia. This number includes six species and one subspecies described as new to science in this paper: Stenocercus fimbriatus, Lepidoblepharis hoogmoedi, Leposoma osvaldoi, L. snethlageae, Tretioscincus oriximinensis, Tupinambis longilineus, and Anolis nitens tandai. Stenocercus dumerilii is resurrected from the synonymy of S. tricristatus. Bachia cophias is considered a junior synonym of B. flavescens. B. peruana is a new record from Brazil. Anolis nitens has priority over A. chrysolepis. The Amazonian Tupinambis is shown to be T. teguixin (of which T. nigropunctatus is a junior synonym). The name T. merianae should be used for T. teguixin sensu Boulenger (1885b). Mabuya ficta is a junior synonym of M. bistriata, while the name M. nigropunctata should be used for M. bistriata sensu Vanzolini & Williams (1980). Of all species extensive descriptions and ecological data, if available, are presented. A zoogeographical analysis based on the combined distribution maps of the various species shows a main division in Amazonia of a western and an eastern fauna. A southwestern group is also recognised and, although defined by a smaller number of species, a Guianan group. The lizard fauna from Rondonia shows multiple affinities. The distribution of lizards in enclaves of open formations in Amazonia does not support the idea of continuous areas of savannas throughout Amazonia in relatively recent times.

558 citations

Journal ArticleDOI
TL;DR: A molecular phylogenetic study of 69 squamate species suggests that similar states in Sphenodon and Iguania result from homoplasy, and species previously placed in Scleroglossa, Varanoidea, and several other higher taxa do not form monophyletic groups.
Abstract: Squamate reptiles (snakes, lizards, and amphisbaenians) serve as model systems for evolutionary studies of a variety of morphological and behavioral traits, and phylogeny is crucial to many generalizations derived from such studies. Specifically, the traditional dichotomy between Iguania (anoles, iguanas, chameleons, etc.) and Scleroglossa (skinks, geckos, snakes, etc.) has been correlated with major evolutionary shifts within Squamata. We present a molecular phylogenetic study of 69 squamate species using approximately 4600 (2876 parsimony-informative) base pairs (bp) of DNA sequence data from the nuclear genes RAG-1(approximately 2750 bp) and c-mos(approximately 360 bp) and the mitochondrial ND2 region (approximately 1500 bp), sampling all major clades and most major subclades. Under our hypothesis, species previously placed in Iguania, Anguimorpha, and almost all recognized squamate families form strongly supported monophyletic groups. However, species previously placed in Scleroglossa, Varanoidea, and several other higher taxa do not form monophyletic groups. Iguania, the traditional sister group of Scleroglossa, is actually highly nested within Scleroglossa. This unconventional rooting does not seem to be due to long-branch attraction, base composition biases among taxa, or convergence caused by similar selective forces acting on nonsister taxa. Studies of functional tongue morphology and feeding mode have contrasted the similar states found in Sphenodon(the nearest outgroup to squamates) and Iguania with those of Scleroglossa, but our findings suggest that similar states in Sphenodonand Iguania result from homoplasy. Snakes, amphisbaenians, and dibamid lizards, limbless forms whose phylogenetic positions historically have been impossible to place with confidence, are not grouped together and appear to have evolved this condition independently. Amphisbaenians are the sister group of lacertids, and dibamid lizards diverged early in squamate evolutionary history. Snakes are grouped with iguanians, lacertiforms, and anguimorphs, but are not nested within anguimorphs.

428 citations

Journal ArticleDOI
TL;DR: This study relied on traditionally prepared specimens as well as high-resolution computed tomography scans that afforded unprecendented access to the cranial anatomy of Squamata to provide an unparalleled sample of the phenotype enabling it to more fully explore the extreme incongruences between molecular and morphological topologies for the squamate tree of life.
Abstract: We assembled a dataset of 192 carefully selected species—51 extinct and 141 extant—and 976 apomorphies distributed among 610 phenotypic characters to investigate the phylogeny of Squamata (“lizards,” including snakes and amphisbaenians). These data enabled us to infer a tree much like those derived from previous morphological analyses, but with better support for some key clades. There are also several novel elements, some of which pose striking departures from traditional ideas about lizard evolution (e.g., that mosasaurs and polyglyphanodontians are on the scleroglossan stem, rather than parts of the crown, and related to varanoids and teiids, respectively). Long-bodied, limb-reduced, “snake-like” fossorial lizards—most notably dibamids, amphisbaenians and snakes—have been and continue to be the chief source of character conflict in squamate morphological phylogenetics. Carnivorous lizards (especially snakes, mosasaurs and varanoids) have proven a close second. Genetic data, presumably less bur...

424 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
2023142
2022304
202166
202077
201961