Filtern
Dokumenttyp
Sprache
- Englisch (4)
Volltext vorhanden
- ja (4)
Gehört zur Bibliographie
- nein (4)
Schlagworte
- Guiana Shield (4) (entfernen)
This chapter argues that paying attention to the weather and its associated processes of geological, biological, and social weathering can destabilize knowledge traditions that insist on dichotomies. Looking to specific histories and current conditions in Guyana and Suriname, this chapter shows how notions of weathering can accommodate a wide range of referents, ranging from the weathering of rock to socio-political and historical afterlives of violent colonial displacements.
The frog Pristimantis marmoratus was originally described als Hylodes marmoratus by George A. Boulenger in 1900 based on a single specimen reported to have been collected at the foot of Mount Roraima in Guyana in 1898. We herein discuss the exact location of the type locality of P. marmoratus and provide a redescription of the species based on new material from Kaieteur National Park and from the slopes of Maringma-tepui in Guyana. We also describe the previously unknown vocalization and breeding ecology of the species, and conducted an exploratory molecular analysis of the phylogenetic relationships within the genus Pristimantis represented by the members of the "unistrigatus species group" in the Guiana Shield. Pristimantis marmoratus is a small-sized species mainly distinguished from its known Guiana Shield congeners by the combination of F I < II, SVL ≤ 20.4 in males, presence of vocal slits in males, granular/pustulate dorsal skin with well-developed scapular ridges, basal webbing between fingers, fringes in fingers and toes, crossed iris, diffuse yellow or pale green wash on groin, and absence of flashy colour on axillary/pre-axillary region. The advertisement call consists of a single note repeated at a rate of ca 11 calls/min with a dominant frequency ranging from 2756 to 3101 Hz. Pristimantis marmoratus is primarily arboreal, exclusively active at dusk, and propably restricted to the pristine rainforests of the Pantepui uplands and highlands, east of the Gran Sabana between ca 600 and 1800 m above sea level. Preliminary molecular analyses recovered Pristimantis marmoratus as sister to an unnamed species from the Eastern Guiana Shield. On grounds of the newly established distributional extent we suggest maintaining the IUCN conservation status as Least Concern.
Two new colourful species of direct-developing frogs of the genus Pristimantis are described from the summit of two isolated tepuis (sandstone table mountains) in the Eastern Pantepui District of the Guiana Shield highlands. Pristimantis jamescameroni sp. nov. is described from the summit of Aprada-tepui from 2557-2571 m elevation, and P. imthurni sp. nov. is described from the summit of Ptaritepui at 2471 m elevation. Both species share the absence of a differentiated tympanic membrane and external tympanic annulus (but presence of tiny pharyngeal ostia), the presence of nuptial pads in males, and the presence of lateral fringes on fingers and toes, a combination of characters that immediately distinguishes them from all other known Pantepui congeners. The two new species are morphologically similar to each other and are phylogenetically closely related, but they can be distinguished based on colour pattern and morphological characters such as head proportions, dorsal skin texture, and condition of the supratympanic fold. The IUCN conservation status of the new species is considered as Endangered (EN) owing to their apparent very restricted ranges. The number of described Pristimantis species occurring exclusively on tepui (and faunistically related granitic mountains) summits and upper slopes now reaches eleven.
We herein present the first annotated anuran checklist for the Brazilian state of Amapá, eastern Amazonia, based on a thorough literature review. We recorded the occurrence of 111 species belonging to 13 anuran families distributed across 48 localities throughout Amapá, within two biomes. Among these species, 62.5% occur exclusively in the Tropical Moist Broadleaf Forest biome, ~8% occur exclusively in the Tropical Savanna biome, and ~29% occur in both. Two species were considered endemic to Amapá and were registered only in the central portion of the state. Regarding the conservation status, only one species (Dendropsophus amicorum) is classified as threatened, assigned to the “critically endangered” category. The other species are categorized as either “least concern” or “data deficient” (85 and 8, respectively), whereas 21 are not evaluated. The current annotated list contributes to the incipient knowledge on anuran species richness in Amapá and, despite the research regarding anuran taxonomy has considerably progressed over the past 20 years, there is still much to do. Our data highlight the need for trained taxonomists to develop research in the state.