Scaling evolutionary trees to time is essential for understanding the origins of clades. Recently developed methods allow including the entire fossil record known for the group of interest and eliminated the need for specifying prior distributions for node ages. Here we apply the fossilized birth-death (FBD) approach to reconstruct the diversification timeline of the viperines (subfamily Viperinae). Leer más.
The phenomenon of fluorescence can be used by animals to change effective colouration or patterning, potentially to serve functions including intra- and interspecific signalling. Initially believed to be restricted to marine animals, fluorescent colours are now being described in an increasing number of terrestrial species. Here, we describe unique, highly fluorescent patterns in two species of pumpkin toadlets (Brachycephalus ephippium and B. pitanga). Leer más.
Hoy en día, las salamandras pardas del sur se encuentran en menos del 1 % de sus antiguas áreas de distribución. ¿Qué sucedió? Un grupo de científicos busca la respuesta para evitar la extinción. Leer más.
Hay una pandemia en el horizonte. Más del 40 por ciento de las especies de salamandra estadounidenses ya están amenazadas de extinción. ¿Las exterminará la llegada de un nuevo patógeno? El patógeno fúngico llamado Batrachochytrium salamandrivorans (Bsal) ha eliminado casi por completo varias poblaciones de salamandra común en Europa y los biólogos piensan que podría ser cuestión de tiempo que llegue a Norteamérica. Leer más.
We describe a new species of giant spitting cobra, Naja ashei sp. nov., from eastern and north-eastern Africa. The species was previously regarded as a colour phase of the black-necked spitting cobra, N. nigricollis. However, mtDNA sequence data show it to be more closely related to N. mossambica than N. nigricollis. The new species is diagnosable from all other African spitting cobras by the possession of a unique clade of mtDNA haplotypes and a combination of colour pattern and scalation characteristics. Its distribution includes the dry lowlands of northern and eastern Kenya, north-eastern Uganda, southern Ethiopia and southern Somalia. Leer más.
