Despite advances within particular groups, systematics of the Teiidae has long been unsatisfactory, because fewmorphological characters have been described for this family. Consequently, most species have been assigned to the large,polyphyletic, and poorly defined genera Ameiva and Cnemidophorus. We describe 137 morphological characters andscore them for most species of Neotropical Teiidae. Important, but previously undescribed, character suites include pupilshape; the frontal ridge; longitudinal division of the interparietal; the rostral groove; patterns of supraciliary fusion; thepreauricular skin fold; the “toothy” first supralabial; modified apical granules; the pectoral sulcus; expansion of scales atthe heel; tibiotarsal shields; scales between the digital lamellae along the postaxial edges of the toes; scale surfacemicrostructure of macrohoneycomb, macroridges, or lamellae; distribution patterns and morphology of lenticular scaleorgans; types of epidermal generation glands; and several hemipenial structures. We propose a new taxonomy of theTeiidae based on recovered evolutionary history and numerous morphological characters surveyed in this study. Werecognize three subfamilies: Callopistinae new subfamily, Teiinae Estes et al., and Tupinambinae Estes et al. To resolvepolyphyly of Ameiva and Cnemidophorus, we erect four new genera for various groups of Neotropical Teiidae: Ameivulanew genus, Aurivela new genus, Contomastix new genus, and Medopheos new genus. We resurrect Holcosus Cope fromthe synonymy of Ameiva and Salvator Duméril and Bibron from the synonymy of Tupinambis. On the basis of sharedderived characters, we propose new species groups of our redefined Ameiva and Cnemidophorus. We incorporate our newcharacters into a key to the genera and species groups of Teiidae. A phylogenetic hypothesis of Teiidae based onmorphological characters differs substantially from hypotheses based on mitochondrial DNA. The phylogeny based onmorphology is consistent with well-established biogeographic patterns of Neotropical vertebrates and explains extreme morphological divergence in such genera as Kentropyx and Aurivela.

Species in the genus Bothrops s. l. are extraordinarily variable in ecology and geography, compared with other genera in the subfamily Crotalinae. In contrast to the trend of splitting large and variable groups into smaller, more ecologically and phenotypically cohesive genera, the genus Bothrops has remained speciose. In addition, previous phylogenetic analyses have found Bothrops to be paraphyletic with respect to the genus Bothriopsis. Taxonomic arguments exist for synonymizing Bothriopsis with Bothrops, and for splitting Bothrops into smaller genera, but the greatest hindrance to taxonomic revision has been incomplete phylogenetic information. We present a phylogeny of Bothrops, Bothriopsis, and Bothrocophias based on 85 characters of morphology and 2343 bp of four mitochondrial gene regions, and with significantly greater taxonomic coverage than previous studies. The combined data provide improved support over independent datasets, and support the existence of discrete species groups within Bothrops. The monophyly and distinctness of these groups warrant recognition at the generic level, and we propose a new taxonomic arrangement to reflect these findings.

A new method of coding polymorphic multiistate characters for phylogenetic analysis is presented. By dividing such characters into subcharacters, their frequency distributions can be represented with discrete states. Differential weighting is used to counter the effect of representing one character with multiple characters. The new method, generalized frequency coding (GFC), is potentially superior to previously used methods in that it incorporates more information and is applicable to both qualitative and quantitative characters. When applied to a previously published data set that includes both types of polymorphic multistate characters, the method performed well, as assessed with g1 and nonparametric bootstrap statistics and giving results congruent with those of other studies. The data set was also used to compare GFC with both gap-weighting and Manhattan distance step matrix coding. On these grounds and for philosophical reasons, we consider GFC to be a better estimator of phylogeny.

The distal oberhautchen and proximal beta layer of 41 species and every genus of cordylid and gerrhosaurid lizard were examined with a scanning electron microscope. Scale organs in these families are concentrated on the face, and scale organs occur singly or in pairs below the keel on the dorsals of cordylids but not gerrhosaurids. Most species examined possess primitive, lenticular scale organs. Unique and previously unknown, projecting scale organs occur in two species of Cordylus. Scale organs appear to be absent in species of Chamaesaura. The scale surfaces of cordylids are covered in macrohoneycomb. Individual compartments of cordylid macrohoneycomb are not intracellular structures but may be overlain by apparent oberhautchen cells. In some cordylid species, part of each cell is free and projects away from the scale surface as a pointed flap. Gerrhosaurids lack macrohoneycomb. Instead, their scale surfaces are covered in lamellae without dentate borders, 50-100 times as long as wide. The epidermis of Platysaurus is unique among cordylids in possessing lamellae 1-8 times as wide as long that overlap macrohoneycomb in some regions of the body. The scale surfaces of Cordylus cordylus undergo an ontogenetic change similar to that recently described for the xenosaurid genus Shinisaurus. Phylogenetic analysis of scale surface features allows the partitioning of Cordylus into three species groups and Chamaesaura into two species groups. Synapomorphies of the species of Chamaesaura, the species of Platysaurus, and the genera of the gerrhosaurids are also described. © 1995 Wiley-Liss, Inc.

No abstract

No abstract

No abstract

No abstract