Bull. nat. Hist. Mus. Lond. (Zool.) 63(1): 1-12 



Issued 26 June 1997 



A new species of Microgale (Insectivora, 

 Tenrecidae), with comments on the status of 

 four other taxa of shrew tenrecs 



THE 

 HIST 



PAULINA D. JENKINS^ k 



Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD. 



CHRISTOPHER J. RAX WORTHY 



Division of Herpetology, University of Michigan, Museum of Zoology, Ann Arbor, Michigan 481 



RONALD A. NUSSBAUM 



Division of Herpetology, University of Michigan, Museum of Zoology, Ann Arbor, Michigan 48109, USA 



31 Jul 100/ 



PRESENTED 



09. USA. 



SYNOPSIS. A new species of Microgale is described from rainforest localities in Madagascar. Evidence is presented that M. 

 drouhardi is a distinct species, with M. melanorrhachis as a synonym, and similarly that M. pulla is a synonym of M. parvula. 



, 





INTRODUCTION 



The Family Tenrecidae is currently divided into four subfamilies, 

 three of which, the Geogalinae, Oryzorictinae and Tenrecinae are 

 endemic to Madagascar, while the fourth, the Potamogalinae, occurs 

 only inAfrica (see Hutterer, 1 993). Within this highly diverse family, 

 the most diverse of all are the shrew tenrecs belonging to the 

 Oryzorictine genus Microgale Thomas, 1882, which at various 

 times has been subdivided into four genera or sub-genera, compris- 

 ing as many as 22 species. Despite the revision by MacPhee (1987) 

 based on specimens available at that time in museum collections, in 

 which only ten species were considered valid, the species composi- 

 tion of Microgale remains unclear. Subsequent to this revision, the 

 number of specimens of Microgale available has probably doubled 

 as a result of several recent expeditions to different localities in 

 Madagascar. These expeditions have attempted to provide an inven- 

 tory of the small mammal fauna, for taxonomic and biogeographic 

 purposes and for the development of conservation strategies. These 

 intensive surveys suggested that some of the species synonymised in 

 MacPhee's revision, are in fact distinct (Nicoll & Rathbun, 1990; 

 Raxworthy & Nussbaum, 1994; Stephenson, 1995; Jenkins et al, 

 1996; Goodman et al, 1996) and revealed the presence of several 

 undescribed species of Microgale (Jenkins, 1988, 1992, 1993; Jenkins 

 et al. 1996). Specimens from five widely separated localities, dis- 

 tinctive in external appearance, are believed to be conspecific and to 

 represent an additional undescribed species, the description of which 

 is given below. 



During the course of these surveys, good samples of adult and 

 juvenile specimens of Microgale were collected from a wide range 

 of localities, allowing re-evaluation of the specific status of four 

 taxa, M. drouhardi Grandidier, 1934, M. parvula Grandidier, 1934, 

 M. melanorrhachis Morrison-Scott, 1948 and M. pulla Jenkins, 

 1988. The first three species were originally described from juvenile 

 specimens, a problematic situation in this genus, where the decidu- 

 ous and permanent dentitions may differ considerably, so causing 

 confusion over the correct specific attribution of juveniles and adults 

 (see MacPhee, 1987). Microgale drouhardi, M. parvula and M. 

 pulla were also known only from their respective type localities, and 

 M. parvula andM. pulla only from their holotypes. BothM. drouhardi 



and M. melanorrhachis are of uncertain status and were considered 

 to be synonyms of M. cowani Thomas, 1882 by MacPhee (1987) but 

 evidence is presented below to show that M. drouhardi is a distinct 

 species with which M. melanorrhachis is synonymous. Likewise, it 

 is demonstrated that M. pulla is a synonym of M. parvula. 



MATERIALS AND METHODS 



In each of the surveys listed above, small mammals were collected 

 in pitfall traps, usually operating for five to ten days at each site. For 

 detailed information on collection methods see Raxworthy & 

 Nussbaum (1994; 1996) and Goodman et al (1996). 



Measurements, in millimetres, were recorded using dial calipers 

 and a microscope measuring stage. External measurements include 

 head and body length (HB) from the tip of the nose to the 

 distalmost point of the body (at base of tail); tail length (TL) 

 measured from the base of the tail to the end of the distalmost 

 vertebra, excluding terminal hairs; hind foot length (HF) from the 

 heel to the distal part of the longest toe, excluding the claw; ear 

 length (EL) measured from the notch at the base of the ear to the 

 distalmost edge of the pinna; weight (WT) measured with Pesola 

 spring scales, animals weighing less than 10 gm within 0.2 gm and 

 10-100 gm within 0.5 gm. Cranial measurements were taken as 

 follows: condyloincisive length (CIL) cranial length from first 

 upper incisor to occipital condyle; upper toothrow length (UTL) 

 from anterior of first upper incisor to posterior of third upper 

 molar, parallel to the long axis of the skull; breadth of braincase 

 (BB) the greatest distance measured across the squamosals; height 

 of braincase (BH) greatest height in the midline from basioccipital 

 to parietal. 



The dental nomenclature follows that of Mills (1966), Swindler 

 (1976), Butler & Greenwood (1979) and MacPhee (1987). Dental 

 notations are given in parentheses in the text; premaxillary and 

 maxillary teeth are denoted by upper case, mandibular teeth by 

 lower case, as follows: incisor (I7i), canine (C/c), premolar (P/p), 

 molar (M/m); a prefix 'd' indicates deciduous teeth, thus (dl) refers 

 to a deciduous upper incisor. 



Age classes are defined as follows: 



©The Natural History Museum, 1997 



