Tribe, Christopher James;
(1996)
The neotropical rodent genus 'Rhipidomys' (Cricetidae: Sigmodontinae) - A taxonomic revision.
Doctoral thesis (Ph.D), UCL (University College London).
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Abstract
South American climbing mice and rats, Rhipidomys, occur in forests, plantations and rural dwellings throughout tropical South America. The genus belongs to the thomasomyine group, an informal assemblage of plesiomorphous Sigmodontinae. Over 1700 museum specimens were examined, with the aim of providing a coherent taxonomic framework for future work. A shortage of discrete and consistent characters prevented the use of strict cladistic methodology; instead, morphological assessments were supported by multivariate (especially principal components) analyses. The morphometric data were first assessed for measurement error, ontogenetic variation and sexual dimorphism; measurements with most variation from these sources were excluded from subsequent analyses. The genus is characterized by a combination of reddish-brown colour, long tufted tail, broad feet with long toes, long vibrissae and large eyes; the skull has a small zygomatic notch, squared or ridged supraorbital edges, large oval braincase and short palate. Three main divisions of the genus are recognized. The R. fulviventer section contains four species - fulviventer, wetzeli, caucensis and ochrogaster - inhabiting montane forests in the northern Andes and Guiana Highlands of Colombia and Venezuela; they share grey-based ventral pelage, dark extremities, a rounded interorbital region, broad braincase, and (except for caucensis) a primitive carotid circulation pattern; R. fulviventer consists of a chain of isolated subspecies, including venustus. The monospecific R. macconnelli section is restricted to the Guiana Highlands of Venezuela; it differs in certain external characters - darker colour (especially ventrally), longer metatarsals, bicoloured tail - but is similar cranially. The R. leucodactylus section is usually paler with broad feet, stronger cranial ridges and a derived carotid circulation pattern, and occurs mainly at lower levels. It contains 13 species: couesi, leucodactylus, modicus, austrinus, latimanus (including venezuelae), nitela, emiliae, macrurus, mastacalis and four as yet unnamed. Three species occur in NE Brazil; in SE Brazil the material currently available does not permit a clear-cut arrangement.
Type: | Thesis (Doctoral) |
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Qualification: | Ph.D |
Title: | The neotropical rodent genus 'Rhipidomys' (Cricetidae: Sigmodontinae) - A taxonomic revision |
Open access status: | An open access version is available from UCL Discovery |
Language: | English |
Additional information: | Thesis digitised by ProQuest. |
Keywords: | Biological sciences |
URI: | https://discovery.ucl.ac.uk/id/eprint/10119506 |
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