Toads of the genus Melanophryniscus are known since the mid-late 19th Century, and the first skeletal description was made early in 1875. However, it was not until the 1970s that osteological variation was discussed in a more inclusive taxonomic scenario. Derived from this, the first morphological synapomorphies proposed for the genus represented skeletal traits extracted from the few species considered in those studies. In this work, we examined the skeletons of 25 of the 29 currently recognized species of Melanophryniscus, plus three species under description, to examine their osteological variation and discuss the validity of those synapomorphic characters proposed, not only by analyzing their distribution within the genus but also by comparing them with the skeletal data available in the bibliography for other early branching bufonids. Our results show that main variations within the genus are related to changes in absolute body size and some proportions of postcranial elements. Except for M. setiba, an early diverging species that exhibits a number of autapomorphies, most skeletal traits are quite conserved throughout the genus. Members of the Melanophryniscus tumifrons group are distinctive by their nasal region, which tends to be taller than in other species, dome-shaped, and strongly exostosed. Most features considered diagnostic of the genus occur in other early branching bufonids, and are highly polymorphic, and this challenges earlier discussions on putative synapomorphies. For instance, exostosed frontoparietals only occur in M. setiba and M. klappenbachi, and the condition was also recorded for Osornophryne. The frontoparietal fontanelle, if present, may show different shapes and sizes (often similar to those in Osornophryne and some species of Atelopus). The zygomatic ramus of the squamosal may be absent or present as a small process, as described for some species of Atelopus, Osornophryne, and Truebella. Finally, posterolateral processes of the hyoid were observed in some early diverging species and hence we propose an alternative interpretation on its presence and distribution in the genus.

Chemosensory searching in squamates with specialized tongue–vomeronasal systems is well-documented. By tongue-flicking, these reptiles gather important chemical cues from their environment to guide their feeding behavior. Strike-induced chemosensory searching (SICS) is a specific expression of chemosensory reception that is central to the predatory strategy used by venomous reptiles that strike, release, and relocate their prey. This complex behavioral process consists of multiple sequential steps and has been mainly studied in viperids, particularly rattlesnakes. Although this phenomenon has been extensively researched, there is no comprehensive review of the SICS literature. Here, we provide such a review, centered on the idea that SICS is a result of suppression, and then enhancement, of chemosensory searching that serves as a key element of the ambush hunting strategy that most viperid snakes use to consume large and well-defended prey. SICS is also present in other venomous and nonvenomous taxa, and we include a taxonomic categorization of SICS studies in our review. We summarize the key findings discovered during decades of research into this remarkable feeding behavior and highlight areas where our knowledge remains incomplete in an effort to foster further research that will increase our understanding of reptilian feeding ecology.

Recently isolated populations offer a good biological model to infer the evolutionary forces responsible for the current divergences across populations. We coupled genetic, morphometric, ecological, and demographic analyses from three island populations of the endemic Balearic Wall Lizard, Podarcis lilfordi, (Balearic archipelago, Spain) to infer the mechanisms underlying the observed differences in body size. For each population, we described plant community structure, derived a biotic capacity index, and used individual-based data on 1369 lizards captured and released during 6 yr (2009–2015) to estimate population density and body growth patterns. We used genetic data collected on 80 individuals (∼27 for each population) to infer genetic divergences across islets and population history. Body size divergences cannot be explained by the ecological or population characteristics. Individual growth was slower in the smallest island, where lizards reached the largest average body size. In addition to having the highest density, results suggested that resource availability does not constrain asymptotic body size, but the speed at which individuals reach it does. The Approximate Bayesian Computation used to infer population history from genetic data supported the occurrence of two bottlenecks in the islet with the highest anthropogenic footprint. We emphasize the need to integrate ecological and genetic data and the importance of considering the effects of past human disturbance as an additional force in being able to model present island fauna.

Behavioral biologists have long been fascinated with the diversity of animal signals produced in the contexts of courtship and same-sex competition. In these contexts many lizards engage in conspicuous bobbing displays, and numerous studies have been devoted to describing these displays. Traditionally, bobbing displays are partitioned into units whose durations (and sometimes head amplitudes) are measured. Recently, Macedonia et al. (2019) introduced use of the Discrete Fourier Transform (DFT) as an alternative to unit-based variables for characterizing species-specific traits in display structure of Galápagos Lava Lizards (Microlophus spp.). The relative success of the two methods was not compared directly, however, because the homology of display units among species was uncertain. Here we overcome this problem using the “grahami series” of Anolis lizards—a monophyletic radiation of seven species on Jamaica and Grand Cayman. Our study had three primary goals. Our first goal was to discover whether DFT-based measures, unit-based measures, or their combination provided the best means to capture taxon-specific distinctiveness in display structure. To this end, we quantified bobbing displays and used nested analyses of variance (ANOVAs) to determine if particular variables were reliably superior at differentiating populations within a species. We then used principal components analysis to reduce the number of measurement variables, and entered the components into discriminant function analyses to determine which approach best discriminated among taxa. Results showed that no one type of measurement, or measurement combination, emerged as being consistently better at discriminating taxa across comparisons. Our second goal was to test a hypothesis that arose from our findings in Galápagos Lava Lizards—that the DFT may decrease in effectiveness as bobbing display structure increases in complexity. For this test we used four simple and compound display types from the species Anolis reconditus. Results of discriminant function analyses provided mixed support for the hypothesis, and we suggest that a definitive test of DFT performance and display complexity should utilize synthetic displays in which attributes of display structure are varied systematically. Last, we show how bobbing display structure maps onto alternative DNA-based phylogenies of the grahami series anoles. Whereas some species produced derived display types unanticipated from displays of more basal species in this adaptive radiation, others exhibited features that linked them to a particular population of a species in their clade.

Recent higher level phylogenetic analyses of gekkonid lizards of the genus Lepidodactylus uncovered an array of unrecognized species diversity, particularly within the Philippine archipelago. Novel phylogenetic analyses of multilocus data sets suggest that as many as five, previously undescribed, species-level lineages of Scaly-toed Geckos occur in just the northern portions of the archipelago. Here, we evaluate Lepidodactylus species diversity in the Lepidodactylus yami–balioburius clade and describe four new forest species from Luzon Island and surrounding minor island groups. Interestingly, these species are the first endemic Lepidodactylus taxa described from Luzon proper and peripheral islands. In this first review of Philippine Scaly-toed Gecko diversity in nearly half a century, we use a suite of morphological characters along with molecular data to delimit evolutionary lineages. All species described in this paper can be distinguished from congeners by an array of discrete external traits; all are also monophyletic groups, separated in our phylogenetic analyses of the mitochondrial ND2 gene. This study increases significantly the number of known Scaly-toed Geckos in the Philippines from 7 to 11, which is likely still an underestimate of the species diversity in this understudied clade.

We revisit the question of species diversity among Mindanao Fanged Frogs of the Limnonectes magnus complex consisting of L. magnus, L. diuatus, L. ferneri, and a previously hypothesized putative new species, inferred in the first molecular phylogenetic studies of the genus almost 2 decades ago. Using a multilocus molecular deoxyribonucleic acid sequence data set and comprehensive sampling of 161 individuals from throughout the Mindanao Pleistocene aggregate island complex landmasses (a distinct faunal region of the southern Philippines) we characterize geographically structured genetic diversity, focusing on the phylogenetic placement of individuals from each species' type locality. We also present new morphometric data from large samples of freshly collected material from the type localities of each included species; together with examination of the name-bearing original type specimens, we conclude that an overestimation of species diversity has occurred and has been exacerbated by the indiscriminate acceptance of the hypothesis of the existence of widespread cryptic species in this group. We place L. ferneri in synonymy with L. diuatus, clarify the identification of the latter taxon with respect to L. magnus, and apply this name to the widespread, generalist, highly variable giant Fanged Frog distributed throughout the Mindanao faunal region of the southern Philippines.