Variation in the growth and development of the hind limbs in frogs of the genus Telmatobius (Anura: Telmatobiidae).

There are remarkable interspecific differences in the sizes of the larvae of Andean frogs of the genus Telmatobius. This size variation seems to be associated with the duration of the larval stage and may affect the hind-limb morphology in Telmatobius. Larval, juvenile, and adult Telmatobius rubigo and T. oxycephalus were examined to determine the variation in relative sizes of hind-limb elements, their growth patterns during postmetamorphic life, and skeletal ontogeny. The results showed that the proportionately shorter hind limbs of T. rubigo relative to those of T. oxycephalus are associated with the protracted development and ossification of hind limbs during the prolonged larval life of T. rubigo. Postmetamorphically, the hind limbs grew faster than the body in juveniles of both species in contrast to the relative growth rates of the hind limbs and bodies of the adults. The growth phase of juvenile T. rubigo seems shorter than that of juvenile T. oxycephalus; possibly, this heightens the difference in the relative lengths of hind limbs after metamorphosis. Temperature affects the effects of thyroid hormone on growth and development, and T. rubigo lives at much higher, colder elevations than does T. oxycephalus. It is not clear whether the developmental differences described here are plastic (i.e., environmentally induced) or genetically fixed in each species.

Where is the enigmatic Telmatobius halli Noble 1938? Rediscovery and clarification of a frog species not seen for 80 years.

Telmatobius halli was the first endemic Telmatobius species described in Chile, reported by Noble in 1938 near the locality of Ollagüe, in the high Andean zone of the Antofagasta region. To this date, there are no specimens assignable to this species other than the type series; although many expeditions have tried to search for T. halli, they have been unsuccessful, but they have found and described new species around this area. In order to clarify the origin of the enigmatic T. halli, we reviewed the itinerary of the expedition carried out by F. G. Hall in the Chilean Altiplano, to place a putative type locality. We contrast the morphology of the holotype, with that of recently collected specimens from the new putative type locality, to confirm the population's identity; and finally, we perform phylogenetic analyses in order to clarify the systematic position of this taxon. The historical review of the expedition that collected these frogs shows that it is likely that Telmatobius halli had been collected near Collahuasi, about 50 km northwest of Ollagüe, site that we have assigned as a putative type locality for T. halli. The morphological analyses support this hypothesis, while phylogenetic results show that the specimens assigned to this species form a monophyletic group, and is a sister clade of T. chusmisensis. Thus, we propose that the type locality of T. halli be changed from "around Ollagüe" to the area of the Copaquire ravine, so its distribution would be restricted to this system and Choja-Chijlla ravine, both in the high Andean zone of the Región de Tarapacá, Chile.