A new snouted treefrog (Anura, Hylidae, Scinax) from fluvial islands of the Juruena River, southern Brazilian Amazonia.

Southern Amazonia is one of the less-explored regions by anuran taxonomists. We describe a small new species of snouted treefrog, genus Scinax, from this region, from a fluvial archipelago in the Juruena River, state of Mato Grosso, Brazil. The description is based on external morphology of adults and tadpoles, advertisement call and molecular data.

Conserved chromatin and repetitive patterns reveal slow genome evolution in frogs.

Frogs are an ecologically diverse and phylogenetically ancient group of anuran amphibians that include important vertebrate cell and developmental model systems, notably the genus Xenopus. Here we report a high-quality reference genome sequence for the western clawed frog, Xenopus tropicalis, along with draft chromosome-scale sequences of three distantly related emerging model frog species, Eleutherodactylus coqui, Engystomops pustulosus, and Hymenochirus boettgeri. Frog chromosomes have remained remarkably stable since the Mesozoic Era, with limited Robertsonian (i.

Modularity, homology, heterochrony: Gavin de Beer's legacy to the mammalian skull.

Modularity (segmentation), homology and heterochrony were essential concepts embraced by Gavin de Beer in his studies of the development and evolution of the vertebrate skull. While his pioneering contributions have stood the test of time, our understanding of the biological processes that underlie each concept has evolved. We assess de Beer's initial training as an experimental embryologist; his switch to comparative and descriptive studies of skulls, jaws and middle ear ossicles; and his later research on the mammalian skull, including his approach to head segmentation.