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Adhesive toe pads have evolved numerous times over lizard evolutionary history, most notably in geckos. Despite significant variation in adult toe pad morphology across independent origins of toe pads, early developmental patterns of toe pad morphogenesis are similar among distantly related species. In these distant phylogenetic comparisons, toe pad variation is achieved during the later stages of development. We aimed to understand how toe pad variation is generated among species sharing a single evolutionary origin of toe pads (house geckos— Hemidactylus). We investigated toe pad functional variation and developmental patterns in three species of Hemidactylus , ranging from highly scansorial (H. platyurus), to less scansorial (H. turcicus), to fully terrestrial (H. imbricatus). We found that H. platyurus generated significantly greater frictional adhesive force and exhibited much larger toe pad area relative to the other two species. Furthermore, differences in the offset of toe pad extension phase during embryonic development results in the variable morphologies seen in adults. Taken together, we demonstrate how morphological variation is generated in a complex structure during development and how that variation relates in important functional outcomes. [ABSTRACT FROM AUTHOR]

The article explores the suitability of this gecko species for developmental biology research. Topics include criteria for selecting model species in developmental studies, the unique morphological features of geckos that make them ideal for evolutionary research, and the specific advantages of using Lepidodactylus lugubris in laboratory settings due to its ease of housing and high fecundity.

Osteoderms are bony deposits that form within the dermal layer of skin in vertebrates. Within geckos, osteoderms are uncommon, only described inGekko geckoand the genusTarentola. A previous report of osteoderms in the Afro-Malagasy gekkonid genusGeckolepishas been questioned due to the extreme skin fragility and regional integumentary loss within the group. We re-evaluated the integument anatomy ofGeckolepis maculatausing µCT scanning, histology, and clearing and staining to verify the presence or absence of osteoderms and, if present, to characterise and compare their morphology to the osteoderms ofGekko geckoandTarentola, as well as osteoderm diversity within squamates. Osteoderms were confirmed present inGeckolepis maculata; however, these osteoderms are compound, imbricating, squamous elements that are morphologically similar to the dermal ossifications observed in scincids and gerrhosaurids, whileG. geckoandTarentolapossess plate-like and granular osteoderms. Our results suggest that osteoderms have independently evolved at least three times within the Gekkota and that epidermal anatomy may be a better predictor of osteoderm morphology than ancestral history. Further research is required to investigate the regenerative capability ofGeckolepisosteoderms following skin autotomy. [ABSTRACT FROM AUTHOR]

The article offers information on Trimeresurus flavomaculatus is a large and semi-arboreal viperid snake endemic to the Philippines and the body size is variable among the 50 described species of Trimeresurus, with maximum total lengths ranging from 480 mm from Norman, Oklahoma.

The article reports on the maximum size of Aristelliger praesignis (Jamaican Croaking Lizard).

Chatogekko amazonicus is a miniaturized gecko from northern South America and is among the smallest of toe pad bearing lizards. The toe pads of C. amazonicus are miniscule, between 18% and 27% of the plantar surface area. We aimed to investigate the relationship between adhesive toe pad morphology, body size, and adhesive capabilities. Using scanning electron microscopy, we determine that the adhesive pads of C. amazonicus exhibit branched setae similar to those of other geckos, but that are generally much smaller. When compared with other gecko taxa, we show that C. amazonicus setae occupy a similar range of seta length: snout-vent length ratio and aspect ratio as other gekkonoid species (i.e. Gekkonidae, Phyllodactylidae, and Sphaerodactylidae). We demonstrate that C. amazonicus-even with its relatively small toe pads-is capable of climbing a smooth glass surface at a nearly vertical angle. We suggest that sphaerodactylids like C. amazonicus offer an excellent system for studying toe pad morphology and function in relation to miniaturization., (© 2024 The Author(s). The Anatomical Record published by Wiley Periodicals LLC on behalf of American Association for Anatomy.)

Many species of sphaerodactyl gecko exhibit sexual dichromatism. In particular, dichromatism plays an important role in intersexual signaling for Sphaerodactylus. Furthermore, some species exhibit polymorphism in male color and pattern. Here, we describe a regional male color morph of Sphaerodactylus macrolepis from St. Croix. After generating both mitochondrial and nuclear phylogenies, we found that individuals with the St. Croix-specific yellow/orange head morph are part of the S. macrolepis clade. This distinct color morph likely contributed to the turbulent taxonomic history of the S. macrolepis species group. Given the documented diversity of the color patterns in this group and that sexual signals evolve rapidly, we suggest S. macrolepis is an excellent group to study the ecological and evolutionary consequences of dichromatism and polymorphism.

Well-resolved phylogenetic hypotheses and ontogenetic data are often necessary for investigating the evolution of structural novelty. The Sphaerodactylidae comprises 12 genera of predominantly miniaturized geckos. The genera Aristelliger and Teratoscincus are exceptions, with taxa reaching snout-to-vent lengths far exceeding those of other sphaerodactylids. These two genera possess enigmatic, supraorbital ossifications-parafrontal bones-which are encountered nowhere else among squamates. At the time of their discovery, these structures were believed to be the result of evolutionary convergence. Although relationships between other sphaerodactylids remain unresolved, recent molecular and morphological data have supported a close relationship between Aristelliger and Teratoscincus. We investigated the ontogeny of parafrontal bones to better understand relationships between sphaerodactylid body size and the presence of parafrontals, and to evaluate whether ontogenetic data support the homology of parafrontals between Aristelliger and Teratoscincus. We hypothesize that the parafrontals of Aristelliger and Teratoscincus are homologous and that there is a threshold body size in sphaerodactylids below which parafrontals do not develop, thus explaining their absence from the miniaturized taxa. The presence of parafrontals was investigated in all sphaerodactylid genera using cleared-and-stained, radiographed, and skeletonized specimens. Total surface area of parafrontals was measured for seven species of Aristelliger and six species of Teratoscincus throughout their ontogeny. Histology was used to investigate the cellular composition of the parafrontals throughout their ontogeny. Our data suggest that parafrontals have evolved in parallel from a homologous, parafrontal precursor and that the onset of parafrontal development is not strictly dependent on a threshold body size. Anat Rec, 301:581-606, 2018. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)