Evolutionary reversals, including re-evolution of lost structures, are commonly found in phylogenetic studies. However, we lack an understanding of how these reversals happen mechanistically. A snake-like body form has evolved many times in vertebrates, and occasionally a quadrupedal form has re-evolved, including in Brachymeles lizards. We use body form and locomotion data for species ranging from snake-like to quadrupedal to address how...

Elongate, snake- or eel-like, body forms have evolved convergently many times in most major lineages of vertebrates. Despite studies of various clades with elongate species, we still lack an understanding of their evolutionary dynamics and distribution on the vertebrate tree of life. We also do not know whether this convergence in body form coincides with convergence at other biological levels. Here, we...

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Evolutionary simplification of autopodial structures is a major theme in studies of body-form evolution. Previous studies on amniotes have supported Morse’s law, that is, that the first digit reduced is Digit I, followed by Digit V. Furthermore, the question of reversibility for evolutionary digit loss and its implications for “Dollo’s law” remains controversial. Here, we provide an analysis of limb and digit...

Cameron Siler, Katrina Menard, and the OU field crew (Austin Carriere, Elyse Ellsworth, Sierra Smith & Sam Eliades) arrived safely in Manilla on May 22 and had a day or so to explore the city while waiting for collaborators Dr. Duncan Irschick (UMass-Amherst) and Dr. Phillip Bergman (Clark University). They have now wrapped up collecting at their first site in Cayagan Province on Luzon Island and are now traveling...

We describe a new digitless scincid lizard of the genus Brachymeles from northern Luzon and Camiguin Norte islands in the Philippines. This species belongs to the Brachymeles bonitae Complex, and both molecular and morphological data confirm that this species is distinct from all other congeners. Formerly considered to be a single widespread species, this group of species has been the focus of...

A new species of slender skink is described from the Philippines. The species is endemic to Lubang Island, and is assigned to the Brachymeles bonitae Complex based on phenotypic and genetic data. Specimens were collected from Lubang Island between 1991 and 2012, and were examined based on morphological data (qualitative traits, meristic counts, and mensural measurements). Published genetic sequence data from phylogenetic...

Studies of the diversity of Philippine amphibians and reptiles have resulted in the continued description of cryptic species. Species formerly thought to range across multiple recognized faunal regions are now considered to be assemblages of multiple unique species, each restricted to a single faunal region. This pattern continues to hold true when considering Philippine skinks of the genus Brachymeles. Recent studies have...

We review the species of the Brachymeles bonitae Complex (B. bonitae and B. tridactylus) and describe an additional two new species in this highly specialized, limb-reduced, endemic Philippine clade of fossorial lizards. For more than 4 decades, B. bonitae has been recognized as a single ‘‘widespread’’ species, a perception that has persisted as a result of limited sampling and similar overall morphology...

There are only four groups of scincid lizards at the genus level which have species that are fully limbed as well as species without limbs. All species are known to burrow and live in dry, rotting material inside decaying logs or in loose soil and leaves. Many different populations within the genus Brachymeles look very similar, so identifying separate species within this...