Norntatesamerican MUSEUM PUBLISHED by the AMERICAN MUSEUM of NATURAL HISTORY CENTRAL PARK WEST at 79TH STREET, NEW YORK, N.Y

NorntatesAMERICAN MUSEUM PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET, NEW YORK, N.Y. 10024 Number 3087, 55 pp., 24 figures, 5 tables February 16, 1994

Systematic Studies of Madagascar's Endemic Rodents (Muroidea: Nesomyinae): Revision of the Genus Eliurus

MICHAEL D. CARLETON' CONTENTS Abstract ...... 2 Introduction ...... 2 Taxonomic History ...... 3 Materials and Methods. 4 Acknowledgments .7 Characterization of the Genus. 7 External. 7 Cranial and Postcranial Skeleton. 8 Dentition .10 Accounts of Species .10 Eliurus Milne Edwards .11 Eliurus myoxinus Milne Edwards .12 Eliurus minor Major .15

Eliurus majori Thomas ...... 20 Eliurus penicillatus Thomas ...... 23

Eliurus tanala Major ...... 25

Eliurus webbi Ellerman, new rank ...... 33

Eliurus petteri, new species ...... 37

Eliurus ellermani, new species ...... 39

Interspecific Relationships ...... 40

Morphometric Comparisons ...... 42

Phyletic Inferences ...... 43

Natural History Information ...... 48

References ...... 49

' Curator, Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560; Research Associate, Department of Mammalogy, American Museum of Natural History. Copyright American Museum of Natural History 1994 ISSN 0003-0082 / Price $6.30 2 AMERICAN MUSEUM NOVITATES NO. 3087

Appendix 1: Gazetteer ...... 52 Appendix 2: Descriptive Statistics of Eliurus ...... 54

ABSTRACT

Among Madagascar's seven genera of endemic tail tuft, proportional craniodental differentiation, rodents (Nesomyinae Major, 1897), members of and possession ofcertain qualitative cranial traits. the genus Eliurus are readily identified by their Each species account summarizes the taxon's di- soft fur, broad hindfeet, and a long tail bearing a agnostic traits, distributional information, and the conspicuous terminal tuft. Based on examination limited data on ecology and reproduction. The of approximately 200 museum specimens repre- greatest species diversity of Eliurus occurs within senting 42 collecting localities, eight species, with- humid, evergreen forests in the east, where seven out subspecific divisions, are recognized: E. myox- of the eight species are found. One species, E. inus Milne Edwards, E. minor Major, E. majori myoxinus, is confined to dry deciduous forest and Thomas, E. penicillatus Thomas, E. tanala Major, scrub formations in the west and south. External, E. webbi Ellerman, and two species described cranial, dental, and skeletal features uniting the herein as new. Discrimination between species re- species of Eliurus are amplified as a basis for im- lies principally on size, chromatic and textural fea- proved diagnosis ofthe genus and for future study tures of the pelage, development and color of the of intergeneric relationships.

INTRODUCTION Compared to other groups of Muroidea, wet tropical forests in eastern Madagascar as the rodents indigenous to Madagascar com- well as dry forest associations in the west. prise a meager number of species, ten, which Webb (1954) appropriately dubbed these ro- represent seven genera (Petter, 1972, 1975; dents "tufted-tailed rats" in recognition of Honacki et al., 1982; Corbet and Hill, 1991). the usually dense penicillation of hairs to- The ten species are generally believed to have ward the end of their tail, a development originated from a common ancestor that un- which constitutes the cardinal external trait derwent a modest radiation during a long pe- ofthe genus. To date, six taxa ofEliurus have riod ofisolation, perhaps since the early Mio- been named, five ofthem originally described cene, on the island-continent (Simpson, 1945; as species, but recent classifications acknowl- Lavocat, 1978). Consistent with the conven- edge only a large- and small-bodied species, tional interpretation (but see Ellerman, 1941), E. myoxinus and E. minor, respectively (Pet- the several forms have been arranged as an ter, 1975; Honacki et al., 1982; Corbet and endemic subfamily, Nesomyinae (Major, Hill, 1991). 1897), which is placed within either the Cri- In their review of museum collections of cetidae, Muridae, or a broadly defined family Nesomyinae, however, Carleton and Schmidt Nesomyidae (see Carleton and Musser, 1984, (1990) argued that the current definition of for review ofmuroid classifications). The ap- two species severely underestimates the bi- parently unremarkable speciation of neso- ological variety within Eliurus. Indeed, fur- myines has been accompanied by impressive ther taxonomic study will probably reveal the morphological and ecological divergence be- genus as by far the most speciose ofthe seven tween them-from gerbil-like (Macrotarso- genera of Nesomyinae. The central purpose mys) to volelike (Brachyuromys) to rabbitlike ofthe present study is to begin to substantiate (Hypogeomys) forms-such that the seven this contention. In doing so, I present the genera recognized are well circumscribed and morphological basis for the identification of their specific members readily identifiable. eight species, two of them newly described One of those morphologically distinctive herein, summarize their geographic distri- genera is Eliurus, which embraces several butions, consolidate the limited data on their broad-footed, long-tailed taxa known from ecology and reproductive biology, and offer 1 994 CARLETON: MADAGASCAR'S RODENTS 3 a preliminary evaluation of interspecific re- ed no new rodent discoveries, and in his clas- lationships within Eliurus. This report is the sification ofRodentia, Ellerman (1941) listed second in a series (see Carleton and Schmidt, all five taxa ofEliurus as species as they were 1990) intended to document existing muse- originally described. However, Ellerman did um collections of Nesomyinae as a frame- remark (p. 76) that "There seems no extreme work for pursuing higher-level phylogenetic difference between the named forms except investigations of the group. that minor is constantly smaller than the others in the small series examined." Ellerman's impression in this regard foreshadowed his TAXONOMIc HISTORY later taxonomic action that established the In describing his new genus and species current view of species diversity within the Eliurus myoxinus, Milne Edwards (1885) ac- genus. knowledged its external resemblance, partic- In his 1949 addendum to The Families and ularly as observed in its bushy tail, to dormice Genera ofLivingRodents, Ellerman reported (family Myoxidae) and to Platacanthomys on an important collection of Malagasy ro- (formerly included with myoxids). The ety- dents gathered by Cecil S. Webb during the mology ofEliurus myoxinus reflected this su- Second World War (see Webb, 1954). The perficial impression, both for the generic fine series of many nesomyine taxa obtained (Eliomys, a European dormouse) and for the by Webb enhanced Ellerman's appreciation specific (Myoxides, an early family name of of local and geographic variation within Eli- dormice) epithets adopted. Despite the affin- urus and persuaded him (1949: 161) to rank ity suggested by its scientific name, Milne all of the named forms, except E. minor, as Edwards recognized that the dentition ofEli- subspecies of E. myoxinus: ".... I am re- urus aligned his new form with the Muridae garding all the above named forms [that is, (sensu lato) and, in particular, with the other majori, tanala, and penicillatus] as well- genera of Malagasy rodents then known, marked races of the first-named E. myoxi- namely Nesomys, Brachytarsomys, and Hy- nus." Ellerman obviously held reservations pogeomys. over this action, for he continued: "It is per- The zoological explorations ofC. I. Forsyth haps a rather extreme view, but the differ- Major in the middle 1890s contributed im- ences indicated and in material available to portant additions to the systematic knowl- me do not seem to warrant full specific rank edge of Eliurus (Major, 1896b). Four new for any of them." Within this broad context species were eventually described from these ofintraspecific variation, he (1949) described collections, two each by Oldfield Thomas and E. myoxinus webbi as another distinctive race, by Forsyth Major: E. majori Thomas, 1895 this one named from the coastal lowlands of (type locality, Ambohimitambo); E. minor southeast Madagascar (20 mi S Farafangana) Major, 1896a (type locality, Ampitambe); E. but also occurring at higher elevations (about tanala Major, 1896a (type locality, Vinani- 1500 m) in mountains east of Ivohibe and in telo); and E. penicillatus Thomas, 1908 (type lowland rainforest far to the northeast around locality, Ampitambe). In contrast to the west- Antongil Bay. coast provenance ofE. myoxinus, all ofthese Ellerman's (1949) arrangement ofthe high- forms originated from the large humid forest ly differentiated races ofE. myoxinus is better block in eastern Madagascar. Diagnostic fea- appreciated when considered within the de- tures of the several new species principally cade of the 1940s, a period marked by the concerned differences in overall size, pilosity emerging biological species concept and the of the tail, and occurrence of a white tip on convention of using the subspecies category the tail. to somehow index patterns of intraspecific The number of taxa within Eliurus re- variation. His interpretation of species mained stable for several decades after this boundaries within Eliurus, consisting of a brief episode of description. The Mission large-bodied polytypic myoxinus that fre- Zoologique Franco-Anglo-Americaine (= quently co-occurs with the smaller monotyp- MZFAA) to Madagascar, conducted from ic minor, was consistent with taxonomic April 1929 to May 1931 (Rand, 1936), yield- practices engendered by the new species phi- 4 AMERICAN MUSEUM NOVITATES NO. 3087 losophy, especially with respect to the treat- the distributional maps are discussed by ment of morphologically similar, allopatric Carleton and Schmidt (1990). Principal lo- forms. Thus he observed (1949: 162) that calities and their coordinates for specimens "No two forms here regarded as races of E. of Eliurus reported herein are provided in myoxinus occur together, so far as I know." Appendix 1. Ellerman's interpretation has since re- In view of the small sample sizes and in- mained the accepted species classification of adequate geographic representation available Eliurus (Petter, 1972, 1975; Corbet and Hill, for most nesomyine taxa, descriptive statis- 1980,^ 1991; Honacki et al., 1982). Never- tics and multivariate analyses were of neces- theless, as I shall document below, this sim- sity based on composite OTUs recognized as ple view misrepresents the biological diver- follows. sity within Eliurus. The constancy of traits advanced for discriminating the various de- Eliurus minor scribed forms is greater than appreciated by OTU 1: N = 5, from vicinity of Hiaraka, Ellerman, and new distributional records Maroantsetra, and Andapa. provide instances of sympatry or contiguous OTU 2: N = 9, from vicinity of Didy, Im- allopatry among them. The collective evi- erimandrosa, and Perinet. dence recommends the elevation ofall named OTU 3: N = 2, from Ampitambe (type lo- forms ofE. myoxinus to species and the rec- cality). ognition of yet other undescribed popula- OTU 4: N = 13, from vicinity of Ambod- tions. iamontana and Andraina. OTU 5: N = 7, from vicinity ofVondrozo. MATERIALS AND METHODS E. myoxinus myoxinus Specimens and Analytical Samples: This OTU 6: N = 9, from vicinity of Bevilany. revision is based on the examination of ap- OTU 7: N = 9, from vicinity of Analabe, proximately 200 specimens of Eliurus, con- Beroboka, Morondava, Tsilam- sisting principally of study skins with asso- bana (type locality), and Tulear. ciated skulls, from the following collections, E. m. majori each preceded by the museum acronym OTU 8: N = 5, from Mount D'Ambre, adopted throughout the paper. Ambohimitambo (type locality), AMNH American Museum of Natural History, and Andringitra. New York City E. m. penicillatus BMNH British Museum (Natural History), OTU 9: N = 16, from Ampitambe (type London locality). FMNH Field Museum ofNatural History, Chi- cago E. m. tanala LMCM Merseyside County Museums, Liver- OTU 10: N = 18, from vicinity of Lohar- pool iandava and Perinet. MCZ Museum ofComparative Zoology, Har- OTU 1 1: N = 18, from vicinity of Ambod- vard University iamontana, Andrambovato, and MNHN Museum National d'Histoire Naturelle, Paris Vohiparara. RMNH Rijksmuseum van Natuurlijke Histoire, OTU 12: N = 3, from Vinanitelo (type lo- Leiden cality). USNM National Museum of Natural History, E. m. webbi Washington D.C. = UZMC Universitets Zoologisk Museum, Co- OTU 13: N 5, from Mount d'Ambre. penhagen OTU 14: N = 10, from vicinity of Andran- ofotsy, Ankovana, Antalaha, An- The specimens examined are generally list- talavia, Hiaraka, Maroantsetra, ed according to the provenance supplied by and Rantabe. the collector. The location ofcollecting sites, OTU 15: N = 20, from vicinity ofAndram- current geographic synonyms, and the deter- bovato, Ifanadiana, and Kianja- mination of coordinates used for preparing vato. 1 994 CARLETON: MADAGASCAR'S RODENTS 5

OTU 16: N = 6, from mountains east ofIvo- field crew-namely minor (OTU 4), tanala hibe. (OTU 11), and webbi (OTU 15). External OTU 17: N = 14, from vicinity of Farafan- measurements are provided for the purpose gana (type locality) and Vondrozo. of general description and to aid field iden- Eliurus new species 1 tification but were not employed for the mul- OTU 18: N = 3, from tivariate comparisons of samples. vicinity of Fanovana Sixteen cranial and two dental dimensions (type locality), Perinet, and Rogez. were measured to the nearest 0.1 mm using Eliurus new species 2 hand-held digital calipers accurate to 0.03 OTU 19: N = 2, from Hiaraka (type locality) mm. These measurements, and their abbre- and north of Rogez. viations as used herein, are defined and listed alphabetically below (see fig. 1). AGE CRITERIA AND MEASUREMENTS: Spec- imens were initially assigned to one of five BBC breadth of the braincase: the distance broad age classes based on a combination of measured across the hamular processes pelage condition and dental wear: juvenile, ofthe squamosals at the point where they subadult, and young-, full-, and old-adult. are adnate to the mastoid bullae. However, sample sizes proved to be too small BIF breadth ofincisive foramina: the greatest and good locality series too few to meaning- transverse expanse across both incisive fully assess either age or geographic variation, foramina, typically measured at the level except in a Statisical of the premaxillary-maxillary suture. qualitative fashion. BM Is breadth ofbony palate across first upper analyses were thus limited to "adult" animals molars: the transverse distance between as recognized by the absence of the gray ju- the labial edges ofthe upper first molars, venile-subadult pelage and by the possession generally at their middle lamina. of fully erupted, though sometimes unworn, BOC breadth across the occipital condyles: the third molars. distance between the lateral edge of the A maximum of 7 external and 18 cranio- dorsal lobes of the exoccipital condyles. dental variables was recorded for each spec- BR breadth ofrostrum: the distance between imen examined. Total length (TOTL), lengths the lateralmost projection of the naso- of tail (TL), hind foot (HFL), and ear (EL), lacrimal capsules, locatedjust anterior to all given in whole millimeters (mm), are those the zygomatic plates. recorded by the collector on the skin label. BZP breadth of zygomatic plate: the shortest Length of head-and-body (HBL) was ob- distance between the anterior and pos- tained either as listed by the collector or by terior margins of the zygomatic plate, subtraction TL generally near its midsection. of from TOTL. Weight (WT) DAB depth of the auditory bulla: the distance in grams was also transcribed from specimen between the dorsal rim of the auditory labels, although this datum is generally un- bullae, directly above the external au- available for specimens preserved before the ditory meatus, and its ventralmost cur- 1960s. Nor did early collectors always pro- vature; the line of this dimension lies in vide external dimensions, and where avail- the transverse plane of the skull and able, their measurement protocol is often un- oblique to its saggital plane. clear for certain variables (for example, EL IOB interorbital breadth: the minimum dis- from the crown or from the notch, and HFL tance across the frontal bones between with the claw or without). As an index of the orbital fossae, generally at the mid- general body size, I therefore measured dry point of the interorbital constriction. hind foot length (DHFL), including"the claw, LBP length of bony palate: the shortest dis- to the nearest 0.5 mm on skins tance between the anterior margin ofthe museum whose mesopterygoid fossa and the posterior metatarsal and phalangeal bones remained terminus of the left incisive foramen. straightly aligned. Shrinkage of the hindfoot LD length of diastema: the distance, on the on a prepared Eliurus skin averages about 1- same side, between the anterior edge of 2 mm, as suggested by a comparison ofDHFL the first upper molar and the lesser cur- with HFL for several species recently col- vature ofthe upper incisor, near its emer- lected and standardly measured by the same gence from the incisive alveolus. 6 AMERICAN MUSEUM NOVITATES NO. 3087

I I I % I I WM1 I LM 1-3 L IF I ... I I I I T

DAB Fig. 1. Schematic views of the cranium (dorsal, ventral, lateral), right maxillary molar row, and incisive foramina of an adult Eliurus myoxinus showing the limits of the 18 craniodental measurements recorded for specimens of Eliurus (see Material and Methods for abbreviations and definitions of measurements). 1994 CARLETON: MADAGASCAR'S RODENTS 7

LIF length of incisive foramina: the greatest mutually parsimonious trees was summa- length of one incisive foramen. rized by the strict consensus method. LM1-3 length of maxillary toothrow: a coronal length recorded from the anterior border ACKNOWLEDGMENTS of the first upper molar to the posterior margin of the third. I appreciate the assistance of the curators LR length of rostrum: the distance, taken and museum staff who accommodated my parallel to the longitudinal cranial axis, collection visits or arranged loans, or both, from the posterior border of the zygo- including Guy G. Musser (AMNH); Ian Bish- matic notch to the tips ofthe nasal bones. op, Paula Jenkins, and Jean Ingles (BMNH); ONL occipitonasal length: the distance be- Bruce Patterson (FMNH); Malcolm J. Largen tween the tip of the nasals and the pos- (LMCM); Maria Rutzmoser (MCZ); Francis teriormost edge ofthe occiput,just above Petter and Michel Tranier (MNHN); Chris the foramen magnum. PPB posterior breadth ofbony palate: the least Smeenk (RMNH); and Hans Baag0e and Mo- transverse span of the bony palate, re- gens Andersen (UZMC). The cranial photo- corded at the constriction of the maxil- graphs, distributional maps, and ink draw- lary bones behind the upper third molars ings were prepared by Dave Schmidt, whose and in front of the parapterygoid fossae. care and attention to detail I greatly appre- PPL postpalatal length: a distance measured ciate. The submitted manuscript was criti- along the basicranial midline, from the cally reviewed by James M. Ryan and Robert anterior margin of the mesopterygoid S. Voss whose apt suggestions were, for the fossa to the midventral lip (basion) of most part, readily incorporated; any errors of the foramen magnum. fact or interpretation lay with the author. WM1 width of first upper molar: the crown width of the upper first molar across its middle lamina. CHARACTERIZATION OF THE GENUS ZB zygomatic breadth: the maximum span between the lateral surfaces of the zy- Previous contributions have cursorily pre- gomatic arches, a point generally on the sented the distinctive external and cranial jugal bones and immediately in front of traits of Eliurus. Milne Edwards (1885) the jugal-squamosal suture. stressed only external appearance in his brief description ofthe genus, and Ellerman (1941, MORPHOMETRIC AND PHYLOGENETIC 1949) emphasized its laminate dentition in ANALYSES: Standard descriptive statistics provisionally associating the taxon as the Eliuri within the Murinae. (mean, range, standard deviation) were com- Group subfamily puted for the OTUs. Principal components To avoid repetition of common traits in the and as a were extracted from the variance-covariance species accounts, basis for future matrix and computed using the 18 cranio- phylogenetic study of nesomyines and im- I dental all ofwhich were first trans- proved diagnoses of the genera, here am- variables, plify the skeletal, and dental formed to natural logarithms. Loadings are external, features as expressed as Pearson product-moment cor- characterizing the genus Eliurus relation coefficients of the principal compo- viewed from the present understanding ofits nents with the original external and cranial contents. Anatomical terminology generally variables. All analytic procedures were car- follows Hershkovitz (1962), Carleton (1980), ried out using Systat (Version 4.0, 1988), a and Voss (1988). series of statistical routines programmed for microcomputers. EXTERNAL Phylogenetic relationships were explored Fur soft and fine, consisting of a thick coat using PAUP Version 2.4.1 (Swofford, 1985) ofcover hairs interspersed with coarser guard to find trees of minimal length (branch- and- hairs; dorsal pelage generally longer and bound option) by the criterion ofWagner par- denser than ventral. Guard hairs black simony. Characters were not weighted, and throughout their length, occasionally silver- trees were rooted using a designated outgroup tipped, and protruding little above coat of OTU. The congruent cladistic structure in cover hairs except on rump. Cover hairs 8 AMERICAN MUSEUM NOVITATES NO. 3087

to blackish to tip ofvertebrae, or with a white terminal tuft in two species; hair and epidermis otherwise basically monocolored, or infrequently with pale midventral splotching toward base. Proximal section of tail appearing naked macroscopically, epidermal scales easily discernible; scales arranged as imbricating annuli with triad ofhairs emerging from posterior margin of each scale (this pattern is progressively obscured as the hairs become longer toward the tail tip and mask its scutellation). Forefoot with nail-bearing, stubby pollex, other four digits clawed. Dorsum of meta- carpus and phalanges usually covered with white hairs; palmar surface naked with five prominent pads, consisting of three close-set interdigitals and the paired thenar and hypothenar (fig. 2). Hindfoot comparatively short and broad, Fig. 2. Plantar views ofleft manus and left pes all digits with claws (fig. 2); clothed dorsally of Eliurus majori (AMNH 100854, Montagne with white hairs, sometimes with a dusky d'Ambre-; HFL = 31 mm). Abbreviations: hy, hy- metatarsal streak; ungual tufts ofwhitish hairs pothenar pad; th, thenar pad. arch over full length ofclaws; plantar surface naked from phalanges to heel. Fifth digit rel- chromatically banded, usually tricolored on atively long, its claw reaching to base of claw dorsum and bicolored on venter; basal band of digit IV; claw of hallux extends to middle long and colored some shade of gray; middle of first phalanx of digit II. Plantar pads six band ofvariable length and buffy to dull white; in number, large and fleshy; four interdigital if present, terminal band always short and pads clustered together at base of digits, the dark brown to black. Dorsal-ventral coun- first and fourth occasionally bearing a small- tershading apparent in most species, indis- er, incompletely delineated pad on their outer tinct in two, but without pronounced lateral edge; hypothenar subequal in size to inter- line. Dorsal effect usually some shade of digitals and arranged close to them, thenar brown to brownish gray, bright to somber in conspicuous and elongate. tone; underparts light to medium gray, variably creamy buff. Eyelids darkly pigmented, CRANIAL AND POSTCRANIAL SKELETON surrounded by blackish hairs giving a more or less defined impression of dark eye-rings; Rostrum moderately long, about 33 to 36 pre- or postauricular patches lacking. percent of occipitonasal length, gradually ta- Facial vibrissae include mystacial, sub- pering anteriorly from bulge of nasolacrimal mental, superciliary, genal, and interramal capsules (fig. 3); tips ofnasals usually pointed, groups, the latter two consisting of just one overhanging anterior nares; nasals terminate or two vibrissae each. Pinnae typically darkly posteriorly even with or slightly beyond end pigmented, appearing naked to unaided eye; of rostral processes of premaxillae. Zygo- clothed externally and internally with fine, matic plate narrow, forming a distinct but usually dusky, hairs. Mammae six, distrib- shallow dorsal notch; anterior border ofplate uted as one axillary, one abdominal, and one straight and oriented vertically, its forward inguinal pair. edge not overlapping nasolacrimal capsule in Tail relatively long, ranging from 110 to lateral view; zygomatic arches parallel-sided 135 percent of head and body length, and to slightly bowed in midsection; jugal long noticeably penicillate over distal half to one- and relatively stout, zygomatic processes of quarter ofits length. Caudal hairs light brown squamosal and maxillary well separated. 1994 CARLETON: MADAGASCAR'S RODENTS 9

4 k

A& .1 11

Fig. 3. General conformation (x 1.75) of the cranium and mandible of Eliurus as illustrated by an adult sample of the type species E. myoxinus (BMNH 47.1603, 5 mi E Bevilany; ONL = 36.7 mm).

Interorbital region hourglass-shaped, the coming almost straight over interorbit and supraorbital edges bluntly squared (not rostrum. rounded over); supraorbital shelf or beading Incisive foramina short (40-55% of dias- lacking. Braincase smooth and elongate in temal length), narrow to moderate in width dorsal appearance, without temporal ridges; and terminating well anterior to molars; di- short lambdoidal ridges developed at exoc- astema appearing relatively long (fig. 3). Pos- cipital-squamosal junction but not continu- terior border of bony palate set just anterior ous across supraoccipital; frontoparietal bor- to or even with end of upper third molars, der formed at 900 angle; interparietal broad and lacking posterolateral palatal pits. Pos- and conspicuous but lateral edges not con- terior palatine foramina situated at maxil- tacting squamosals; dorsal profile of skull lopalatine suture near lingual root of second gently and evenly curved over calvarium, be- upper molars; variably expressed according 10 AMERICAN MUSEUM NOVITATES NO. 3087 to species, small and ovate to large and elon- tacting transverse process ofseventh cervical. gate (in the latter condition, the palatine bones Neural spine ofsecond thoracic vertebra con- are pierced by secondary foramina behind the spicuously tall compared to neighboring tho- principal openings). Mesopterygoid fossa with racic spines. Entepicondylar foramen of hu- anterior margin broadly horseshoe-shaped, merus present. lacking a medial spine, and with lateral borders (pterygoid processes) convergent poste- DENTITION riorly. Sphenopalatine vacuities large, exposing about equal lengths of the basisphenoid Upper incisors asulcate and opisthodont, and presphenoid. Parapterygoid plates long their enamel faces colored pale yellow to deep and triangular, slightly recessed to form very orange. Molars moderately hypsodont with shallow fossae; plates mostly bony with single planar occlusal surfaces and principal cusps opening (ventral aspect offoramen ovale) near undefined; molar crowns configured as three their posterolateral corner. lamina oriented nearly transverse to the lon- Tympanic bullae small, with large poster- gitudinal axis of the tooth (fig. 4); individual omedial wedge of the petromastoid visible lamina not connected by medial enamel con- ventrally; passage of internal carotid artery nections (mures and murids) but uniting with marked by notch (carotid canal) just behind wear at their labial and lingual edges. Upper bony eustachian tubes; malleus ofthe parallel and lower third molars two-thirds to sub- type, orbicular apophysis a distinct knob. equal in size to seconds. Upper molars each Subsquamosal fenestra represented by a slight anchored by three roots, lower molars by two. indentation to a moderate notch that defines a short hamular process of the squamosal; ACCOUNTS OF SPECIES postglenoid foramen small, semicircular in Diagnostic traits of species within Eliurus form. Anterior flange of petromastoid (teg- involve variation around a discrete subset of men tympani) contacting and overlapping characters or character complexes. Interspe- posteromedial edge of squamosal, thereby cific size differences, principally as reflected separating the postglenoid and middle lac- in the greatest dimensions of skin and skull, erate foramina. Mastoid bullae small and prove relatively constant, if subtle, in certain bulbous, perforated by posterodorsal fonta- species comparisons. Other than size, the nelle. most useful diagnostic traits of the skin in- Alisphenoid with dorsal segment extend- clude the possession of a white or dark tail ing above level of orbitosphenoid and form- tuft, the relative pilosity of the tail, and de- ing a significant part ofthe rear wall of orbit. gree of dorsal-ventral pelage contrast in col- Masticatory-buccinator foramen separated or; fur texture and length ofpelage are helpful from foramen ovale accessorius by alisphen- when used in combination with other fea- oid strut (except in one species). Carotid cir- tures. culatory pattern derived - stapedial and Some specimens ofdark-tufted species oc- sphenofrontal foramina absent, squamosal- casionally possess white hairs near the end alisphenoid groove absent, and posterior ofthe tail, a condition which may be confused opening of the alisphenoid canal occluded- with a normal white pencil, as observed, for supraorbital and infraorbital branches of the example, in E. tanala. In almost every such stapedial artery presumably lost. instance, however, the white hairs seem to Coronoid process of dentary falcate, arch- have resulted from regenerative hair growth ing dorsally to height ofcondylar process (fig. at the severed end of a tail injured in life. 3); sigmoid notch deep; angular notch broad The tails of these specimens thus appear and shallow; capsular projection oflower in- "bobbed" instead of gradually tapered, and cisor variably expressed, indistinct to clearly their white terminal hairs issue as a dense defined. whorl around the edge of the broken stump, Axial skeleton with 13 thoracic and 7 lum- instead ofthe graded elongation ofhairs that bar vertebrae; sacrum with 2 sacral and 2 occurs toward the tip of unbroken tails. pseudosacral vertebrae. First rib articulates Major themes of craniodental differentia- only with first thoracic vertebra, not con- tion, aside from size, concern the propor- 1 994 CARLETON: MADAGASCAR'S RODENTS I1I

_ Fig. 4. Occlusal views (x 15) of the upper (left member in each pair) and lower (right member in each pair) right molars in representative species ofEliurus, illustrating their planar surface and trilaminar configuration. Left pair, E. majori (MCZ 45929, Ambohimitambo; LM1-3 = 6.26 mm); right pair, E. webbi (USNM 448994, 0.5 km N Kianjavato; LM1-3 = 5.43 mm). tional development of the incisive foramina The general inadequacy of specimen sam- and the molar rows, as well as certain qual- ples also hinders meaningful treatment of itative features-namely, the~~~~~~~~~~~iipresence of su- geographic and age variation. The immatures pernumerary palatal foramina, the patency of all species of Eliurus possess a distinctive of the subsquamosal fenestra, and the con- juvenile pelt, light to medium gray and finer formation of the lower incisor alveolus. The in texture than the adult pelage. The progress small sample sizes and few localities avail- of the molt to the brown adult pelage is thus able for most Eliurus species, however, com- clearly marked. The occurrence of the post- promise rigorous assessment of trait-fre- juvenile molt seems to coincide with the quency data and their utility in species eruption of the upper third molars and pre- discrimination. sumably the attainment of sexual maturity. The sexes of species of Eliurus apparently Individuals in an intermediate stage of the differ little in size and were not segregated for postjuvenile molt typically exhibit fully multivariate computations. One-way analy- erupted molar rows with little or no wear on ses of variance revealed inconsequential ef- the third molars. fects of sex on population variation in the largest population samples ofE. tanala (OTU Genus Eliurus Milne Edwards, 1 1) and E. webbi (OTU 15) (table 1). Only 1885 one of 18 craniodental variables (LM1-3) in one sample (OTU 15) exhibited a significant TYPE SPECIES: Eliurus myoxinus Milne Ed- F-value (P = 0.047), a result which might be wards, 1885, by monotypy. attributable to a Type I sampling error. CoNrENTs: Six specific or subspecific forms 12 AMERICAN MUSEUM NOVITATES NO. 3087

TABLE 1 tion was based. The above specimen is that Results of One-Way Analyses of Variance listed much later as the holotype by Rode (For 18 cranial measurements of population (1945) in his catalog of MNHN rodent types samples ofEliurus tanala [OTU 11 = 106, 89] and and bears the museum's registration number Eliurus webbi [OTU 15 = 56, 13Q].) (1886.1120), the number (330) correspond- E. tanala E. webbi ing to Rode's catalog enumeration, and a third Variable F (sex) F (sex) digit (768) perhaps corresponding to a separate catalog for museum exhibits. In view ONL 0.15 1.02 ZB 1.60 0.10 of the 19th-century catalog date and the ab- BBC 1.64 0.02 sence ofany other E. myoxinus in the MNHN IOB 2.66 0.02 collected prior to the 1960s, I have no basis LR 0.02 0.77 for doubting that this specimen is the one WR 2.27 0.41 upon which Milne Edwards (1885) based his PPL 1.04 0.01 description, as previously concluded without LBP 0.21 1.04 explanatory comment by Rode (1945). LIF 0.64 0.16 For its age and likely past use on exhibit, LD 0.31 0.55 the full-mounted skin on pedestal remains in LM1-3 0.30 4.64* moderately good condition, with the pelage WM1 1.06 1.62 WIF 0.58 0.02 color slightly faded, the pinnae cracked but BMIs 4.03 0.16 still attached, and the tail entire and fully PPB 0.25 0.96 furred; the DHFL, with phalanges slightly DAB 1.51 0.01 curled, measures 25.5 mm. The occipital re- WZP 0.01 0.23 gion ofthe skull is damaged, but its condition BOC 0.43 0.41 is otherwise good with the teeth, bullae, and *= P < .05. nasals intact. The type specimen is a young adult female, as indicated by the light tooth wear and the presence of a near-term fetus of the genus have been described: E. myox- E. Tho- with the skinned carcass in fluid. The exis- inus Milne Edwards, 1885; majori tence of the associated fluid-preserved ma- mas, 1895; E. minor Major, 1896a; E. tanala Major 1896a; E. penicillatus Thomas, 1908; terial was mentioned by Rode (1945). 1949. The TYPE LOCALITY: Given only as "cote ouest and E. myoxinus webbi Ellerman, de Madagascar" by Milne Edwards (1885). basis for regarding each as a valid species is Rode (1945) indicated that the specific lo- discussed in the following species accounts, is of two new cality "Forets de Tsilambany," which together with the description Carleton and Schmidt (1990) equated with forms. Grandidier's (1885) locale "Riv. Tsilam- Eliurus bana" and placed it at approximately 65 km myoxinus SSE Morondava, Toliara Province, 20°50'S, Milne Edwards, 1885 44000'E. Figures 3, 6, 8B, 9B, 12 EMENDED DIAGNosIs: A medium-size (ONL Eliurus myoxinus Milne Edwards, 1885: 1. Allen, = 35-38 mm, DHFL = 25-28 mm) species 1939: 317. Ellerman, 1941: 76. ofEliurus differentiated by the relative short- Eliurus myoxinus myoxinus, Ellerman, 1949: 166. ness of its tail, generally 105 to 110 percent Petter, 1975: 3. of head and body length, and by the posses- HOLOTYPE: MNHN 1886.1120; young sion of a conspicuous, long-haired pencil, adult female; mounted skin, skull, carcass in which extends over the distal 60 to 70 percent fluid with one fetus; collected by Alfred Gran- of the tail length; dorsal coat a light sandy- didier, probably during his 1866 or 1869 voy- brown color and fine-textured; rostrum age along the southwestern coast. strongly tapered with tips ofnasals relatively Milne Edwards did not designate a holo- attenuate; interorbit broad relative to zygo- type for his new genus and species, a common matic expanse; incisive foramina relatively omission for the period, or indicate the na- narrow, their posterior ends only slightly more ture ofthe specimen upon which his descrip- separated than the anterior ends. 1 994 CARLETON: MADAGASCAR'S RODENTS 13

DISTRIBUTION: Dry deciduous forest in shorter rostrum, and elongate braincase. Ros- southwestern Madagascar and xerophilous trum, however, tapers abruptly to a compar- scrub in the south; from the latitude of the atively delicate, attenuated tip. Posterodorsal Tsiribihina River, south to the cape region, borders ofinterorbit more square-edged than and east across the Mandrare River to the in other Eliurus but not forming a projecting vicinity of Bevilany (fig. 5). The species is ledge. Subsquamosal fenestra usually present unknown above 245 m but few altitudes have but small, revealing the petrous portion of been recorded. the periotic but little or none of the brain Aside from the distinctive morphological cavity; hamular process of squamosal stout. features that mark E. myoxinus, its geo- Tympanic bullae relatively most inflated in graphic and ecological distribution reduces the genus (fig. 9B); hence, ventral exposed the possibility of taxonomic confusion. The portion of periotic bone less expansive. In- species, as presently documented in south- cisive foramina moderately long but narrow western and southern Madagascar, is wholly with acutely pointed anterior and posterior allopatric to the several forms of the eastern limits. Supernumerary posterior palatine fo- forests (see figs. 10, 11). Its range may be ramina occasionally present but small. Meso- expected to closely approach those ofE. mi- pterygoid fossa extends slightly between the nor and E. webbi in southeastern Madagas- third molars, ending near the plane of their car; nevertheless, even in this region the oc- third lamina. Anterior face of upper incisors currence of strict ecological sympatry seems deep orange. Alveolus of lower incisor pro- unlikely. jects as slight bulge high on ramus, just below DESCRIPTION: Hairs oftail brush long (12- the anterior edge of sigmoid notch. 15 mm) and conspicuous over approximately COMPARISONS AND REMARKS: The thickly 60-66 percent of tail length (fig. 12). Caudal haired, relatively short tail of E. myoxinus, hairs not arranged in distichous pattern, as combined with its generally lighter brown up- remarked by Milne Edwards (1885), but dis- perparts, immediately distinguishes this form tributed equally around circumference oftail from other Eliurus. Tail length in other spe- in penicillate fashion. No terminal white tuft cies ofEliurus averages conspicuously longer present, hairs monocolored plain brown to than the head-and-body, typically on the or- brownish-black. Scutellation apparent over der of 115 to 125 percent of HBL. In body basal third of tail length, fine basal hairs ex- size, E. myoxinus is smaller than any of the tend about two annuli in length. eastern species except E. minor, and its hind Overall dorsal color a light or sandy brown, foot is relatively shorter and narrower as well pelage texture soft and fine. Hairs of dorsum (Appendix 2). tricolored-basal portion long and plum- The skull of E. myoxinus, however, is beous, middle band narrow and buffy, and comparatively robust, equaling in general size terminal band short and pale brown. Ter- those of E. majori and E. penicillatus but minal bands longer and darker on middor- differing from both species in the many pro- sum and interspersed with fine blackish guard portional features detailed under their ac- hairs. Hairs on midrump 7 to 8 mm long. counts. The relatively broad interorbit and Underparts light gray to creamy gray from short, strongly tapered rostrum of E. myox- throat to groin. Ventral hairs bicolored with inus contrast with the more elongate confor- light gray bases and creamy to white tips. mation ofthe crania ofE. tanala and E. web- Whitish tips about equal in length to gray bi, which are typically larger in most basal bands and impart a light appearance to craniodental dimensions. The otic capsules the venter that contrasts sharply with the dor- ofthe species appear absolutely and relatively sum. Hindfoot relatively short and wide. the largest in the genus, but the univariate Dorsal metatarsus and top ofphalanges white, measurement of the bullae (DAB) inade- without dusky streak. Tops offorepaws whit- quately substantiates this visual impression. ish. The basis ofMilne Edwards' (1885) report Skull stocky and squarish in appearance for the lengths of the head-and-body (155 (figs. 6, 8B), as suggested by its relatively broad mm) and tail (125 mm) ofE. myoxinus, pre- interorbit, parallel-sided zygomatic arches, sumably measured on the type specimen, is 14 AMERICAN MUSEUM NOVITATES NO. 3087

Genus Eliurus E. myoxinus E. minor

200

Fig. 5. Geographic occurrence of the species Eliurus myoxinus and E. minor. Shaded areas indicate highlands above 1000 m. 1 994 CARLETON: MADAGASCAR'S RODENTS 15 obscure. The caudal length of the specimen He further noted that E. myoxinus is "evi- in MNHN is approximately the same as its dently plentiful in the S. W. [dry deciduous] head-and-body length, as can best be ascer- forest but lacking or very scarce in the scrub tained from a fully mounted figure, and no forests." Their fundamentally arboreal na- external data currently accompany the spec- ture clearly impressed Webb, for on another imen. Milne Edwards' figures seemingly ac- specimen tag, he observed: "they [western count for Ellerman's (1949) assertion that the Eliurus] are more arboreal than those from tail of myoxinus is characteristically "shorter the eastern forest and rarely descend to the than head and body, which is an unusual ground." character in the genus." Although the tail Webb's perceptions in this regard must be length ofE. myoxinus is relatively the short- given due attention, since he is one ofthe few est in the genus, its caudal vertebrae do not biologists who has had firsthand experience average shorter than the length of head-and- with Eliurus ofboth western and eastern for- body, nor do those of any other species of ests. In view ofthe abrupt transition between Eliurus known to date (Appendix 2). humid eastern and dry western plant com- Ellerman (1949) remarked on tail length munities in the southeast, the reserve at An- variation among samples oftypical E. myox- dohahela may offer an ideal area to illuminate inus and implied that specimens from the the key ecological requirements influencing region of Beroboka and Tulear possess rela- the distribution of E. myoxinus and to con- tively shorter tails, actually less than head- trast its habits with species ofthe eastern for- and-body length, compared to those from the est domain. vicinity of Bevilany in southeastern Mada- Specimens in juvenile pelage or in postju- gascar. However, the tails of several individ- venile molt to adult pelage were collected uals from the former area, including some during the months of July, August, and Sep- tabulated by Ellerman, were clearly broken tember. Three embryo counts -one, two, and off or bobbed in natural life. Elimination of three fetuses-are available for specimens such specimens from statistical consideration sampled over the same period. reveals that proportional tail length in both ETYMOLOGY: The species name recalls the samples is approximately the same and sur- family name of dormice, Myoxidae, a group passes head-and-body length (Appendix 2). characterized by a densely furred tail some- The taxonomy and distribution ofwestern what remniscent of the strongly penicillate Eliurus must be viewed as preliminary in light tail of this species. ofthe small samples and widely scattered lo- SPECIMENS EXAMINED: 19 as follows: foret calities available, a situation which typifies d'Analabe, 60 km N Morondava (MNHN the scant museum-based documentation of 1980.290, 1982.988); Beroboka, 40 mi N Nesomyinae over vast areas ofwestern Mad- Morondava (BMNH 47.1608-9, 1987.50); 5 agascar in general (see Carleton and Schmidt, mi E Bevilany, Ambovombe-Fort Dauphin 1990). road, the hills, 800 ft (BMNH 47.1600-7, NOTES ON NATURAL HISTORY: All locality 66.2746); Morondava (MNHN 1973.516); records associate this species with dry decid- Tsilambana (MNHN 1886.1120); 35 mi E uous forest and xerophilous scrub formations Tulear (BMNH 47.1610-1, 47.161 la). in southwestern and southern Madagascar. Most museum specimens ofE. myoxinus were obtained by C. S. Webb, whose interesting Eliurus minor Major, 1896a comments on skin tags and published rec- Figures 6, 8A, 9A, 12, 20B ollections (1954) of his trapping experiences provide the best detail available on their hab- Eliurus minor Major, 1896a: 462. Allen, 1939: itat. Almost every specimen tag bears some 317. Ellerman, 1941: 76,1949: 166. Petter, 1975: indication that the animal was trapped on a 3. tree branch. In light of these results, Webb HOLOTYPE: BMNH 97.9.1.153; young adult concluded that "This Eliurus [= myoxinus] male; skin and skull; original number M494; lives in holes in trees, no doubt owing to collected 6 July 1895 by C. I. Forsyth Major. sandy nature of the floor of W. Coast forest TYPE LOCALITY: Given by Major (1896a) [at Beroboka] and to the numerous snakes." as "Ampitambe forest (N. E. Betsileo)." See 16 AMERICAN MUSEUM NOVITATES NO. 3087

-.-ftk *-,WI I :6.

"W~ .- ..

..7"

-40 MW=.&A

Fig. 6. Lateral view (x 1.75) of adult crania and mandibles ofspecies ofEliurus: top, E. myoxinus (BMNH 47.1603, 5 mi E Bevilany; ONL = Fig. 7. Lateral view (x 1.75) of adult crania 36.7 mm); bottom, E. minor(USNM 448979, Am- and mandibles ofspecies ofEliurus: top, E. majori bodiamontana; ONL = 29.3 mm). (MCZ 45929, Ambohimitambo; ONL = 35.2 mm); bottom, E. penicillatus (USNM 49672, Ampi- tambe; ONL = 35.6 mm). Carleton and Schmidt (1990) for the possible location of Ampitambe (= Ampitabe) as 45 tanana and the vicinity ofAntongil Bay south km ESE Fandriana, ca. 900 m, Fianarantsoa to the forested ridge west of Vondrozo (fig. Province, 20°22'S, 47°46'E. 5); altitudinal occurrence broad, from sea lev- EMENDED DIAGNOSIS: A species of Eliurus el around Antongil Bay to 1800 m in moun- characterized by its small size (ONL = 29- tains west of Andapa, near the western and 31 mm, DHFL = 21-24 mm), generally bright upper limits of humid evergreen forest. brown hues of its dorsal fur, and a relatively Eliurus minor ranges broadly in eastern well-developed, dark pencil that extends over Madagascar and has the greatest altitudinal the distal three-fifths to two-thirds of the tail limits thus far documented for a nesomyine length; skull relatively robust for its dimin- rodent. Consistent with its broad geographic utive size and, as viewed in lateral profile, and altitudinal distribution, the species is arch of cranial roof more pronounced. known to co-occur with several other species DISTRIBUTION: Widely found in eastern of eastern Eliurus- including E. penicillatus rainforest from the eastern slopes of Tsara- (Ampitambe), E. tanala (Perinet and vicinity 1 994 CARLETON: MADAGASCAR'S RODENTS 17 ofRanomafana), and E. webbi (west ofMain- posterior ends of upper third molars. Sub- timbato and west of Vondrozo)-and should squamosal fenestra typically present as a be expected to occur with all others, except semicircular notch, defining a short hamular perhaps E. myoxinus. This distributional process but not generally exposing the brain pattern influenced Ellerman (1949) to rec- cavity. Lower incisor alveolus extends to the ognize only two species of Eliurus discrimi- level of the sigmoid notch and forms a mod- nated principally on size. erately developed capsular projection with a DESCRIPTION: Caudal pilosity well devel- weak sulcus (fig. 20B). Incisors relatively oped and covering distal 60 to 66 percent of stout, their enameled surface dull orange. tail length, densest over distal one-half (fig. COMPARISONS AND REMARKS: This species 12). Scutellation moderately defined, evident is immediately recognizable on the basis of over basal one-third oftail. Caudal hairs dark its small bodily and cranial dimensions, the brown to blackish, generally monocolored smallest recorded for the genus (Appendix 2). throughout, and about 7-9 mm long near the Nonetheless, the tail pencil in specimens of terminal tuft. Ventral epidermis of basal tail E. minor is well developed, being conspicu- segment marked with irregular light blotches ous over half ofthe tail length and surpassed in some individuals. Scale hairs near tail base only by that of E. myoxinus in its relative extend over 1.5 to 2 caudal annuli in length. extent. Aside from its small size, the skull of Cover hairs of dorsal pelage basically tri- E. minor is generally unremarkable in its fea- colored, basal two-thirds plumbeous gray, tures and proportions as compared to its larg- with a bright buffy to ochraceous middle band er congeners. One notable exception involves and a short dark tip; fur 9 to 11 mm long on E. minor's strongly flexed cranial vault, which midrump. Overall tone of dorsum much contrasts with the flatter or gently curved pro- brighter than venter, ranging from a light file in other species of Eliurus. grayish brown to a rich cinnamon brown. A Further biological survey will likely dis- concentration of distinctly ochraceous-or- close that the taxonomy ofsmall-bodied Eli- ange hairs accents the flanks and cheeks of urus, here recognized as the one species E. some specimens. Guard hairs fairly numer- minor, is more complicated. In particular, ous and black. Top of metatarsus generally specimens from the lowlands around Anton- dusky, wholly white in some individuals; gil Bay (vicinity of Maroantsetra and west of dorsal surface of phalanges usually white. Maintimbata) are notable for their slightly Pinnae relatively small, clothed externally and larger size and more russet-colored fur. How- internally with fine blackish hairs. ever, the few specimens, some with incom- Cover hairs ofventer bicolored, basal two- plete skulls and known only by one per lo- thirds slate gray and distal portion light buff cality, prohibit definitive clarification oftheir to dull white. General effect of underparts a biological status in relation to populations dark gray with a buffy overwash or highlights; found at higher elevations. The type locality, venter conspicuously demarcated from the Ampitambe, of Major's minor is thought to brighter brown upperparts. be situated around 900 m (Carleton and Despite small size, skull relatively stoutly Schmidt, 1990), a place set within a highland constructed (figs. 8A, 9A). Dorsal profile of zone that encompasses most known exam- cranium conspicuously arched, sloping grad- ples of the species. ually toward the rostrum and sharply to the NOTES ON NATURAL HISTORY: The frag- occiput from the point of strongest flexion mentary comments on the habitats ofE. mi- above the postglenoid foramen (fig. 6). In- nor suggest a broader ecological tolerance than cisive foramina extending little beyond an- those of other Eliurus, although the funda- terior edge of zygomatic plates; foramina lu- mental association of the species with rain- nate in shape, their posterior ends more forest biotopes is clear. The wide altitudinal noticeably separated by the bridge of the belt, sea level to 1800 m, documented for E. maxillary bones. Tiny to moderate-size su- minor includes lowland and montane rain- pernumerary palatal foramina usually pres- forest of various types. In primary lowland ent behind posterior palatine pair. Anterior rainforest near Antongil Bay, Stephenson margin ofmesopterygoid fossa coaligned with (1987) noted the usual occurrence of E. mi- , *f o -Id -

CISCs:

a) C4-

C-1.4

VW1 0

Qu* b

* ^

U,cn

(A 0 o

< .^ m[J 20 AMERICAN MUSEUM NOVITATES NO. 3087 nor, together with E. webbi, in areas with skin, skull, and partial skeleton; original abundant lianas and a sparse understory. In number M166; collected 24 January 1895 by middle elevation, lower-canopied rainforest C. I. Forsyth Major. around Perinet (= Andasibe), an area dis- Thomas (1895) mentioned no number turbed by ongoing logging, specimens were identifying the specimen on which his new collected in denser herbaceous cover found species description was based. Major (1896a), along small streams and among fallen logs in his recognition of E. tanala, incidentally and boulders. Individuals of E. minor have supplied the field number (M166) ofThomas' also been obtained in a mixture ofdense brush type, which concurs with the original skin tag and bamboo bordering a stream (E Andraina) on the specimen in the BMNH, as do the and in lush grass extending 1.5 m tall (N particulars of the other field data and cranial Didy). Placement oftraps that caught E. mi- measurements provided by Thomas (1895). nor include sites on the ground, on low tree TYPE LOCALITY: Given by Thomas (1895) branches, and on fallen trees of small trunk as "Ambolimitambo Forest, Central Mada- diameter. gascar. Alt. 4500 feet," the village name a Indication of reproductive habits is limit- misreading ofMajor's cursive script for Am- ed: a male with scrotal testes is recorded for bohimitambo (about 1200 m, Fianarantsoa May; a specimen in juvenile pelage for July; Province, 20°43'S, 47°23'E). a embryo count of two for August; and a Since Major did not generally record col- lactating female for August. lecting elevations on his field tags, Thomas ETYMOLOGY: Name acknowledges the di- may have extracted the altitude from written minutive size of the species. information received with the first material SPECIMENS EXAMINED: 50 as follows: Am- Major shipped to BMNH from Madagascar. bodiamontana, 7 km (by road) W Ranoma- Regardless of Thomas' source, the figure of fana, 950 m (USNM 448974-80, 448998, 4500 ft is consistent with Major's (1896b) 449248-9); Ampitambe (BMNH 97.9.1.153; later placement of Ambohimitambo at 1400 FMNH 5629); 1 day W Andapa (MNHN to 1500 m. The 1200-m figure is MacPhee's 1932.3513); 14 km E Andraina (USNM (1987) determination based on study of re- 328826); 9 km N Didy, Ambohijanahary cent topographic maps. (USNM 328827); Fianarantsoa, south of EMENDED DIAGNOSIS: A medium-size (ONL (MCZ 45936); Hiaraka, near Maroantsetra = 35-37 mm, DHFL = 27-29 mm) species (MNHN 1981.870); 16 km E Imerimandro- of Eliurus distinguished by a somber, dark- so, Lac Alaotra, 3500 ft (BMNH 47.1618- gray pelage that lacks marked contrast in dor- 22); Mandraka, 45 mi E Tananarive, 4000 ft sal-ventral coloration; tail brush relatively (BMNH 47.1613); 20 km SW Maroantsetra small, noticeable over terminal one-third of (AMNH 100719; BMNH 35.1.8.350); 40 km its length, dark completely to tip; toothrows SW Maroantsetra, 10 km WSW Maintim- comparatively robust, longest in the genus bato (BMNH 1987.107); Perinet, near Mor- (LM1-3 > 6.1 mm); incisive foramina rela- amanga, 3000 ft (AMNH 119712; BMNH tively wide and long. 47.1615-7); Tamatave Road 68 (USNM DISTRIBUTION: Known only from widely 294535); 3 km (by road) NNW Vohiparara, separated localities in the northern (Mon- 1225 m (USNM 449246-7); 20 km W Von- tagne d'Ambre), central (Ambohimitambo), drozo (AMNH 100720-4; BMNH 35.1.8.343- and southern highlands (Anjavidilava, An- 9; MNHN 1932.3511-2, 1932.3514-6). dringitra) (fig. 10); elevational records from 1000 and ca. 1200 m. Eliurus majori Thomas, 1895 No other species of Eliurus is yet known Figures 2, 4, 7, 8C, 9C to co-occur with E. majori, although sympatry with E. minor may be anticipated in Eliurus majori Thomas, 1895: 164. Allen, 1939: view of the latter's wide elevational distri- 317. Ellerman, 1941: 76. bution. On Mt. d'Ambre, the two examples Eliurus myoxinus majori, Ellerman, 1949: 166. of E. majori were collected near the summit Petter, 1975: 3. at 1000 m, but the elevation of collection of HOLOTYPE: BMNH 97.9.1.147; adult male; the series of E. webbi, taken at a later date, 1 994 CARLETON: MADAGASCAR'S RODENTS 21 at d'Ambre is unknown. Elsewhere in Mad- always well defined, usually as an ovoid notch, agascar, this species inhabits rainforest at low exposing petrous portion of periotic and in- to middle elevations. terior ofbraincase. Mandible stocky in form, DESCRIPrION: Tail pencil appears relatively deep and squared off in back, anterior edge less developed, lacking the conspicuous distal of ascending ramus set more perpendicular expansion into a terminal tuft, an effect due to molar occlusal plane. Coronoid process to the more gradual increase in length and rises above condyloid process, together en- density of hairs toward the tip, where they closing a deep sigmoid notch. Lower incisor measure 8 to 10 mm long. Tail dark all round alveolus terminates below the anterior edge to tip, epidermis blackish, hairs dark brown of the sigmoid notch, forming a slight bulge to black, pilosity principally evident over the but not a raised capsular projection with me- distal third ofthe tail length. Scutellation near dial sulcus. the base of tail finely textured. COMPARISONS AND REMARKS: Eliurus ma- General effect ofdorsum a somber blackish jori, together with the morphologically sim- gray, fur soft and thick, somewhat wooly in ilar species E. penicillatus (see following ac- appearance, 10 to 12 mm long on rump. Basal count), is a highly differentiated form within two-thirds of dorsal cover hairs slate gray, the genus. The dull coat color, lack of pro- followed by a short buffy band, and a dark nounced dorsal-ventral chromatic contrast, terminal band; guard hairs relatively dense and weakly developed tail pencil separate the and long. Underparts predominantly dark species on external features from its conge- gray, basal two-thirds ofcover hairs dark gray ners. The general impression ofits dorsal col- and distal one-third dull white. Dorsal-ven- or superficially recalls that of Gymnuromys tral contrast inconspicuous, lacking sharp lat- roberti or an immature Rattus rattus. eral line of demarcation. Top of metatarsus The cranial and dental proportions exhib- dark-furred, phalanges whitish. Pinnae very ited by E. majori (and E. penicillatus) even dark and relatively small. Dark eye-ring ap- more convincingly underscore its uniqueness parent in all of the few known specimens, and collectively serve to identify the species extending between the eyes as a mask in one with confidence. Although smaller in size (MCZ 45929). compared to E. webbi or E. tanala, for ex- Molar rows robust, both relatively and ab- ample, the molars of E. majori are higher- solutely the widest and longest in the genus crowned, wider, and longer (mean about 17% (figs. 4, 9C). Height ofmolar crowns also ap- of occipitonasal length as compared to 14% pears greater than in other Eliurus. Upper in most other species). The upper third mo- third molars subequal in size to second molars are relatively long, subequal to the M2s lars. Face of upper incisors pigmented or- instead of one-halfto two-thirds their size as ange. observed in other species. The long, wide in- Cranium medium-size with relatively short cisive foramina and short palate are also dis- rostrum and elongate braincase (figs. 7, 8C, tinctive compared to the short incisive fo- 9C). Zygomatic arches strongly bowed lat- ramina and comparatively long palates of erally, in some individuals appearing broader other Eliurus. The mesopterygoid fossa in across their anterior aspect. Incisive foram- specimens of E. majori extends farther for- ina wide and long, terminating anterior to ward to reach the plane ofthe middle or front Ml s but appreciably beyond level of leading lamina of M3, rather than the level of the edge of zygomatic plates. Posterior palatine third lamina (minor and myoxinus) or even foramina generally a single pair, round to with the posterior border ofthe tooth (tanala slightly oval in shape, usually lacking super- and webbi). The deep ascending ramus ofthe numerary palatal perforations. Anterior mar- dentary in E. majori contrasts with the more gin ofthe mesopterygoid fossa penetrates be- elongate, low-slung mandibular conforma- tween M3s, to the level ofthe middle or front tion that characterizes other species. lamina of the tooth. The convergence of the The meager samples available for E. ma- long incisive foramina and mesopterygoid jori disallow assessment of variation either fossa imparts a more truncated appearance within or between localities. Aside from age- to the bony palate. Subsquamosal fenestra related size differences, the five known spec- 22 AMERICAN MUSEUM NOVITATES NO. 3087

Genus Eliurus E. majori E. penicillatus E. ellermani E. petteri

200

Fig. 10. Geographic occurrence of the species Eliurus majori, E. penicillatus, E. petteri, and E. ellermani. Shaded areas indicate highlands above 1000 m. 1 994 CARLETON: MADAGASCAR'S RODENTS 23 imens, representing three widely separated male; skin and skull; original number M602; geographic regions, conform closely in mor- collected 20 July 1895 by C. I. Forsyth Major. phology. TYPE LOCALITY: Given by Thomas (1908) In his description of E. tanala, Major as "Ampitambe, N. E. Betsileo, Madagas- (1896a) compared his new species to Tho- car." See Carleton and Schmidt (1990) for mas' (1895) E. majori. Two ofthe specimens the possible location of Ampitambe (= Am- Major so identified by field number are ac- pitabe) as 45 km ESE Fandriana, ca. 900 m, tually examples of E. penicillatus (M430 = Fianarantsoa Province, 20'22'S/47046'E. BMNH 1939.892 and M536 = MNHN EMENDED DIAGNOSIS: Size, pelage colora- 1909.191) that Thomas (1908) subsequently tion, and cranial proportions essentially as in recognized as a distinct species. Although E. majori, except tail tipped with white pen- Thomas (1895) stated that he had only one cil and toothrow shorter (usually < 6.2 mm). specimen at hand for the description of E. DISTRIBUTION: Known only from the type majori, Major (1896a) subsequently listed two locality where examples ofE. minorwere also field numbers belonging to this species, the obtained (fig. 10). type and M159, the latter (MCZ 45929) ac- COMPARISONS AND REMARKS: The distin- quired by Harvard University as part of the guishing features of E. penicillatus only re- Grandidier collection. To date, this is the only quire elaboration with respect to E. majori, other specimen of E. majori known to have which it otherwise recalls in pelage color and been collected by Major at Ambohimitambo. texture and in craniodental size and propor- NOTES ON NATURAL HISTORY: Rand (1936: tions (see figs. 7, 8D, 9D). The cardinal 192) characterized the forest on the summit distinction between them rests with the white- of Montagne d'Ambre as a "damp, green, tipped tail, which typically covers the ter- rainforest type containing many lianas and minal third of its length in specimens of E. mosses." and where "In places ... much her- penicillatus. The white marking involves the baceous ground-cover occurred, though in coloration of both the caudal hairs and the other areas the forest floor was rather open." epidermis and contrasts with the dark hairs The specific character of the vegetation at and epidermis of the proximal tail segment. Ambohimitambo or Anjavidilava where the The dorsum of E. penicillatus also appears other E. majori originated is unknown, but more brownish gray compared to the slate these localities are situated at nearly the same gray of E. majori, but the reliability of such highland elevation or above. Nothing is a subtle contrast in hue is difficult to assess known about the breeding biology ofthe spe- on the basis ofso few specimens ofeach form. cies. Compared to E. majori, examples ofE. pen- ETYMOLOGY: Described in recognition of icillatus average smaller in most craniodental the collector, C. I. Forsyth Major, based pre- dimensions, particularly the size of the mo- sumably on the first shipment of specimens lars and incisive foramina, but their uni- received in BMNH prior to Major's own de- variate ranges do overlap (Appendix 2). parture from Madagascar. Again, the limited samples available disallow SPECIMENS EXAMINED: 5 as follows: Am- meaningful evaluation of the consistency of bohimitambo (BMNH 97.9.1.147; MCZ their apparent disparity in size, but the mean 45929); Andringitra, Anjavidilava (MNHN differences approach in degree that seen be- 1972.602); Montagne d'Ambre, 1000 m tween other morphologically similar forms of (AMNH 100687, 100854). Eliurus whose stature as species can be convincingly documented. Eliurus penicillatus Thomas, 1908 Among the eight species of Eliurus recog- Figures 7, 8D, 9D, 20A nized herein, I regard the evidence for the formal separation ofpenicillatus from majori EliuruspenicillatusThomas, 1908:453. Ellerman, as the weakest. My decision to do so hinges 1941: 76. partly on analogy to the situation concerning Eliurus myoxinus penicillatus, Ellerman, 1949: E. tanala and E. webbi, a pair ofspecies which 166. Petter, 1975: 3. differ in the incidence ofwhite-tail tipping, a HOLOTYPE: BMNH 97.9.1.149; adult fe- chromatic distinction which further corre- 24 AMERICAN MUSEUM NOVITATES NO. 3087

200

Fig. 11. Geographic occurrence of the species Eliurus tanala and E. webbi. Shaded areas indicate highlands above 1000 m. 1994 CARLETON: MADAGASCAR'S RODENTS 25 lates with subtle but consistent craniodental miles south of Fianarantsoa" (ca. 1300 m, contrasts of the two taxa. The possession of Fianarantsoa Province, 21°43'S/47°16'E). a terminal white segment on the tail presum- EMENDED DIAGNOSIS: A large species (ONL ably holds an important infraspecific com- = 38-43 mm, DHFL = 30-36 mm) ofEliurus municative function, as demonstated for the distinguished by a white terminal tuft on its social behavior of other rodent species with tail; penicillate portion relatively short, con- contradistinctive tail tufts (for example, Ei- fined to terminal one-third oftail length, and senberg, 1967). In the case of E. tanala and coarse scutellation exposed over proximal E. webbi, however, the persistence of such two-thirds; molars appearing relatively small differences can be demonstrated within and for robustness of skull; subsquamosal fenes- among larger sample sizes covering a broader tra little expressed, only posterior end of ha- geographic range, which evidence encourages mular process defined, if at all; supernumer- their arrangement as separate biological spe- ary palatal foramina usually present behind cies. Critical resolution of the level of rela- posterior palatine pair. tionship of majori andpenicillatus must await DISTRIBUTION: Middle to upper elevation the acquistion of better samples to assess rainforest, from southeast of Lake Alaotra variation and recourse to other kinds of tax- southward to Vinanitelo (fig. 11); recorded onomic information, such as karyotypic and elevations range between 455 and 1300 m. molecular data. The species has been collected in sympatry NOTES ON NATURAL HISTORY: Ecological with E. minor (Perinet and vicinity of Ran- and reproductive information are lacking for omafana) and E. webbi (NW ofAndrambov- E. penicillatus. Major's field tags and expe- ato, 875 m). Eliurus tanala and E. webbi have dition account (1896a) simply disclose that also been recorded from closely approximate he collected in forest near Ampitambe. The localities in the vicinity of Ranomafana and presumed elevation of Ampitambe around Lohariandava; in each such area, samples of 900 m would place the site within the zone E. tanala are associated with the localities of of wet montane rainforest. higher elevation. ETYMoLoGY: Epithet characterizes the rel- DESCRIPTION: Penicillate portion oftail ap- atively long and fine caudal hairs, which over pears thin and limited to distal one-third of the distal tail segment in this species are high- caudal vertebrae, the terminal section of lighted by their white color. which is tipped with bright white hairs 11 to SPECIMENS EXAMINED: 17 as follows: Am- 13 mm long (fig. 12). The white coloration pitambe (AMNH 31801; BMNH 97.9.1.148- includes the corresponding segment of the 50, 97.9.1.152, 1939.1892; FMNH 5630, caudal epidermis. Terminal white portion of 18822; LMCM A19.4.98.26; MCZ 12435, tuft approximately ranges from 30 to 60 mm 45932; MNHN 1897.536,1909.191; USNM in length, or an average 25 percent of tail 49672; UZMC 1219, 1224, 7941). length. Scutellation coarse and grossly apparent over proximal two-thirds to three- quarters ofthe tail. Basal tail segment appears Eliurus tanala Major, 1896a naked to unaided eye, but covered with short Figures 12, 13, 15C, 16C, 18, 19, 20C scale hairs equal to or less than length of one annulation. Proximal section of caudal epi- Eliurus tanala Major, 1896a: 462. Allen, 1939: dermis evenly dark all around or with irreg- 317. Ellerman, 1941: 76. ular mottling on venter. Eliurus myoxinus tanala, Ellerman, 1949: 166. Cover hairs of dorsum bicolored or tricol- Petter, 1975: 3. ored-basal three-quarters plumbeous gray HOLOTYPE: BMNH 97.9.1.154; adult fe- and the distal one-quarter pale buffy, or male; skin and skull; original number M1358; sometimes tipped with a short black band. collected 27 May 1896 by C. I. Forsyth Ma- Guard hairs numerous, especially toward the jor. middorsum and on rump, and notably longer TYPE LoCALITY: Given by Major (1896a) than cover fur, which is 10 to 12 mm long as "Forest of the Independent Tanala of on midrump. Overall appearance a dark Ikongo, neighbourhood of Vinanitelo, thirty grayish brown to brownish drab, the sides 26 AMERICAN MUSEUM NOVITATES NO. 3087

u WT E 1e z E vi

nb D 1 ,/ i, E

I.I I1

j It %..

ff.

f, I

"", zi!, ',.

minor myoxinus petteri webbi tanala Fig. 12. Development ofcaudal pilosity in five species ofEliurus: E. minor; E. myoxinus; E. petteri; E. webbi; and E. tanala. Full lengths of caudal vertebrae are portrayed to same scale. 1994 CARLETON: MADAGASCAR'S RODENTS 27

W --

rl r9sar z":i.. I 1.

Fig. 14. Lateral view (x 1.75) of adult crania and mandibles ofspecies ofEliurus: top, E. petteri Fig. 13. Lateral view (x 1.75) of adult crania (holotype, MNHN 1961.177, 8 km from Fano- and mandibles ofspecies ofEliurus: top, E. tanala vana; ONL = 38.4 mm); bottom, E. ellermani (USNM 448983, Ambodiamontana; ONL = 42.1 (holotype, MNHN 1981.871, Hiaraka; ONL = 43.8 mm); bottom, E. webbi (USNM 448993, 0.5 km mm). N Kianjavato; ONL = 40.5 mm).

scopically but sparsely furred inside and out- lighter in tone. In some individuals the center side with fine brown hairs. of the back is a noticeably darker gray, sug- Skull large for the genus, with the incisors, gesting an indistinct, broad dorsal band. Hairs zygoma, rostrum, and mandible accordingly ofventral coat bicolored, their proximal half more heavily proportioned (figs. 13, 15C, pale gray and distal half dull white. General 1 6C). Zygomatic arches gently bowed laterad ventral impression a light or buffy gray; some in most specimens, nearly parallel-sided in specimens with variably sized patches ofhairs some. Incisive foramina lunate, their anterior entirely white to base, imparting a creamy and posterior ends acutely pointed, and the gray to nearly white appearance. Dorsum of posterior ends little divergent. Principal pair metapodials and phalanges clothed with dull of posterior palatal foramina elongate and white hairs. Pinnae appear naked macro- narrowly ovate to slitlike, not round-oval; L.

NO% -4 c] C'e

U, C)cis I .11 C- .-4.~f 00 L_ ae

U,(U Cq -4 0 U,Cd

C) .4- . 04 CUd'C

CU .,

I- CU o C

s-C

04CU

v( L.

4. (U)

4.4 Cq

0U, *0

d -ir4

4 I 1r) .;S0 xO

Le AMERICAN MUSEUM NOVITATES NO. 3087

0.3 I I I I I I I I

0.2 tanala e webbi A A WA £ 0.1 *- . 0 A A_& & A &~~~~A :t& ---0&d& 0 o 0.0 && P~AP A 0

A A 0 -0.1 S ~0 . . -0.2

I -0.3 I I -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.4 PC I Fig. 17. Projection of individual specimen scores, based on the 18 log-transformed craniodental variables, onto the first two principal components extracted for selected OTUS of Eliurus tanala (OTUs 10, 11, 12; N = 30) and E. webbi (OTUs 15, 17; N = 26); see table 2. t corresponds to the holotype (BMNH 97.9.1.154) of E. tanala and w to that (BMNH 47.1576) of E. webbi. Regression lines of PC II on PC I differ significantly between species in their Y-intercepts (P < .001) but not their slopes (P = .649). typically one pair of large supernumerary specimens of Eliurus tanala from those of openings set behind posterior palatal foram- other Eliurus. In cranial robustness, E. tan- ina, these sometimes coalesced to form long ala is only surpassed by the new species de- palatal vacuities (fig. 16). Constriction ofpal- scribed below, which lacks a white-tipped tail. ate posterior to third molars relatively pro- In craniodental proportions, E. tanala de- nounced. Anterior border of mesopterygoid parts from E. majori and E. penicillatus in fossa set approximately even with the end of the same manner as do other species of Eli- the third molars. Subsquamosal fenestra ab- urus. Extended comparisons need only be re- sent, or indistinctly defined as a shallow in- served for the discrimination ofE. tanala and dentation above the mastoid bullae; in the E. webbi because the two are numerous in latter condition, only the lateral surface of collections, are morphologically quite simi- the periotic is exposed and a short, broad lar, and are broadly distributed in eastern hamular process is incised. In adult speci- forests where they may occur sympatrically. mens, lower incisor alveolus terminates as a The possession ofa white tail tuft provides pronounced capsular projection with a me- definitive separation ofE. tanala and E. web- dial sulcus; the knobby projection ends be- bi (fig. 12). Curiously, Major (1 896a) neglect- yond the base of the coronoid process and ed to mention this characteristic in his di- sets high on the ascending ramus, just below agnosis of E. tanala, but Ellerman (1949) the ventral rim ofthe sigmoid notch (fig. 20C). emphasized the different terminal caudal col- COMPARISONS AND REMARKS: The combi- ors in naming and comparing E. myoxinus nation oflarge physical size and a tail bearing webbi. The holotype of E. tanala (BMNH a white, gossamer tip serves to distinguish 97.9.1.154) clearly possesses a terminal white 1994 CARLETON: MADAGASCAR'S RODENTS section, at least 25 mm long (the fine tip seems TABLE 2 to be missing), as does the other round skin Results ofPrincipal Component Analysis and One- (FMNH 5631) traceable to Major's type lo- Way ANOVAs cality of Vinanitelo. In the larger series ofE. (Performed on 18 cranial measurements of in- tanala collected around Perinet and Rano- tact specimens of Eliurus tanala [N = 30] and mafana, the constancy of this chromatic dis- Eliurus webbi [N = 26]; see text and fig. 17.) tinction is underscored by its uniform pres- Variable PC I PC II F (species) ence on all specimens with the distal caudal ONL 0.91 0.21 31.1 vertebrae intact. ZB 0.88 0.00 33.4 Aside from their obvious disparity in ex- BBC 0.78 -0.02 23.8 ternal dimensions (see Appendix 2), exami- IOB 0.33 -0.28 6.4 nation of series of E. tanala and E. webbi, LR 0.83 0.23 31.7 side by side, discloses additional subtle dif- WR 0.70 0.03 10.3 ferences in pelage color and tone. Although PPL 0.74 0.35 10.5 the dorsal ground color in both species is some LBP 0.79 -0.03 40.5 shade ofbrown, examples of tanala typically LIF 0.65 0.36 13.8 LD 0.88 0.30 33.0 exhibit a darker grayish cast, whereas those LM1-3 0.74 -0.52 135.7 of webbi are browner and lighter in tone. The WM1 0.78 -0.48 81.7 lighter pelage tone of webbi may result from WIF -0.16 0.33 4.0* the greater length of the subterminal buffy BMIs 0.85 -0.27 68.3 band in its dorsal cover hairs. The fur of PPB 0.35 -0.52 8.0 tanala is slightly coarser in texture than that DAB 0.36 0.18 2.3* observed in webbi, with the guard hairs more WZP 0.80 0.11 25.3 densely distributed and distinctly black in BOC 0.81 -0.04 48.4 color instead of brownish-black. The venter Eigenvalue .033 .006 in specimens of tanala tends toward a light % Variance 53.5 8.9 gray effect in contrast to the grizzled, drab * = NS; all other F values significant at P < .01. gray seen in most webbi. Compared to webbi, the pinnae in tanala appear relatively shorter, and the scales near the base of its tail are larger. In addition, the finer scute hairs in samples of tanala are shorter, seldom over- tal data (fig. 17). Specimens of tanala gen- lapping more than one contiguous ring of erally score greater along the first principal scales. The tail pilosity ofspecimens oftanala component, which reflects their larger size thus appears generally less dense, a contrast and the uniformly high, positive correlations perhaps heightened by the dark-haired ter- of most craniodental variables on that axis minal tuft of webbi. The contrasts related for (table 2). Segregation of tanala and webbi each ofthese traits are best appreciated when along the second principal component pri- comparing series ofthe two species; however, marily reflects differences in robustness ofthe critical identification of single specimens molars (LM 1-3, WM1), mensural traits which should principally rely upon color of the tail also account for the highest F values in anal- tuft and cranial morphology. yses ofvariance (fig. 17; table 2). Age-related The crania of specimens of E. tanala av- size increase undoubtedly explains much of erage slightly larger than those ofE. webbi in the elliptical dispersion of individual scores most variables recorded (Appendix 2). De- within each species sample (for example, see spite their fundamental cranial similarity and Voss and Marcus, 1992). Relative age, as overlap in univariate ranges, separation of judged by tooth wear, must therefore be con- the two species in multivariate space is gen- sidered when attempting to identify un- erally unambiguous. Dual clouds of points knowns, and greater attention should be giv- that correspond to specimens with (tanala) en to dimensions of the toothrows in and without (webbi) white-tipped tails are rendering specific assignments. consistently derived from principal compo- Besides contrast in general size, the crania nent analyses of log-transformed cranioden- of E. tanala and E. webbi also differ in a 32 AMERICAN MUSEUM NOVITATES NO. 3087

Fig. 18. Otic region (approximately x 4.5) and associated foramina in species of Eliurus: left, E. tanala (USNM 448983, Ambodiamontana); right, E. webbi (USNM 448993, 0.5 km N Kianjavato). Abbreviations: ab, auditory bulla; ex, exoccipital; hp, hamular process of squamosal; ms, mastoid; pa, parietal; pgf, postglenoid foramen; sq, squamosal; ssf, subsquamosal fenestra. Note presence of subsquamosal fenestra and corresponding development ofthe hamular process in E. webbi and their absence in E. tanala. number ofqualitative features. The subsqua- For his characterization of E. tanala, Ma- mosal fenestra is weakly expressed or absent jor (1896a) had available at least three spec- in examples oftanala, which correspondingly imens from Vinanitelo, which he referenced have an indistinctly defined hamular process; by field number. One of these (M1358) cor- in those of webbi, the fenestra is usually pa- responds to the type in the BMNH, another tent, revealing the lumen ofthe braincase and (M1510) to a specimen now in the FMNH. forming a short hamular process (fig. 18). The provenance ofthe third specimen (MCZ Specimens of webbi typically lack the large 45690) here listed from Vinanitelo is ques- supernumerary palatal foramina found in tionable since it lacks original field tags. Its tanala; ifpresent in webbi, these openings are geographic source is indicated on secondary notably smaller than the principal posterior labels received with the Grandidier collection palatal pair, not subequal to them as in tanala now at Harvard University. The where- (fig. 19). The mandible in specimens oftanala abouts of Major's third specimen (Ml 515) bears a conspicuous capsular projection that thus remains unknown; it may still exist since sits high on the ascending ramus and ter- a substantial portion of Major's original col- minates behind the anterior rim of the sig- lection was exchanged or otherwise dispersed moid notch; in webbi, the more delicate lower to other museums. incisors produce a smaller capsular projec- NOTES ON NATURAL HISTORY: Locality re- tion and their alveoli end anterior to the bor- cords of E. tanala place the species in ever- der of the sigmoid notch and lower on the green rainforest, generally along a higher al- ascending ramus (fig. 20). Since the posterior titudinal belt (450-1300 m) than E. webbi. palatal constriction averages about the same Description ofthe habitat ofE. tanala is most width (5.1-5.2 mm) in both tanala and web- detailed for forest near Perinet (900-1300 m), bi, it thus appears more sharply indented, where Webb obtained a fine series (BMNH) relative to the palatal breadth, in skulls ofthe in 1939-1940 and where K. Lange and J. former (fig. 16). In the absence of associated Shaw subsequently collected a smaller num- skins, the application ofthese qualitative cri- ber (USNM) in 1962-1963. Within primary teria, together with dimensional data, should rainforest, Lange (field journal, 1962) noted facilitate critical identification. the diversity of microhabitats, including 1994 CARLETON: MADAGASCAR'S RODENTS 33

oPf.

n-,o _ - X Fig. 19. Palatal region (approximately x 7) and associated foramina in species of Eliurus: left, E. tanala (USNM 448983, Ambodiamontana); right, E. webbi (USNM 448993, 0.5 km N Kianjavato). Abbreviations: if, incisive foramen; max, maxillary; mpf, mesopterygoid fossa; pal, palatine; ppf, posterior palatine foramen. Note elongate, slitlike posterior palatine foramina in E. tanala and their short, ovate shape in E. webbi. grassy glades, lush herbaceous growth and inet, near Moramanga, 3000 ft (BMNH viny entanglements along small streams, and 47.1557-72; MNHN 1961.176); 1 km E Per- stands oftree ferns and bamboo. He obtained inet (USNM 341826); 2 km E Perinet (USNM several specimens from a dense concentra- 328828-30); 13 km E Perinet (USNM tion of ferns and other herbaceous plants 341827); Sianaka Forest (BMNH 35.10.12.2, growing beneath the undercut bank of a 36.11.2.1-2; MCZ 29249); 3 km (by road) stream. Webb (1954) collected examples of NNW Vohiparara, 1225 m (USNM 449251- E. tanala on low branches but also on ground 5); Vinanitelo, 30 mi S Fianarantsoa (BMNH sets. 97.9.1.154; FMNH 5631; MCZ 45690). Individuals in gray juvenile pelage or postjuvenile molt have been collected during Oc- Eliurus webbi Ellerman, tober and November. A litter size of two is 1949, new rank recorded for a specimen collected near Ran- Figures 4, 12, 13, 15B, omafana in July. Males in breeding condition 16B, 18, 19, 20D were noted during July and August in the same region. Eliurus myoxinus webbi Ellerman, 1949: 163. Pet- ETYMOLOGY: A patronym identifying the ter, 1975: 3. people of the Tanala tribe who lived in the HOLOTYPE: BMNH 47.1576; adult male; vicinity ofVinanitelo and assisted Major with skin and skull; original number FAR. 5; col- his field collections. lected 14 August 1940 by Cecil S. Webb. SPECIMENS EXAMINED: 49 as follows: Am- TYPE LOCALITY: Given by Ellerman (1949) bodiamontana, 7 km (by road) W Ranoma- as "20 miles south ofFarafangana, south-east fana, 950 m (USNM 448981-90, 448997, coast Madagascar." The skin tag of the ho- 449250); Anosibe, km 55, route Anosibe lotype contains additional locality informa- (MNHN 1961.178); 1 km NW Andrambov- tion: "4 mi from sea, 48°E x 23°S." Webb ato, 875 m (USNM 449256); 10 mi NW Lo- (1954) later acknowledged the village of hariandava, 1500 ft (BMNH 47.1573); Per- Manombo (Fianarantsoa Province, A

AL~ V C

Fig. 20. Lateral view (x 3) of left mandibles of representative species of Eliurus: A, E. penicillatus (UZMC 7941, Ampitambe); B, E. minor (USNM 448979, Ambodiamontana); C, E. tanala (USNM 448983, Ambodiamontana); D, E. webbi (USNM 448993, 0.5 N Kianjavato); E, E. petteri (USNM 341825, 18 km E Perinet). Arrows point to the dorsalmost and posteriormost extension of the incisor alveolus. 1 994 CARLETON: MADAGASCAR'S RODENTS 35

23002'S/47044'E) as base camp for his field- basally and cream to buff distally. Buff ter- work in the nearby forest. minal band long relative to gray proximal EMENDED DIAGNosIs: A moderately large segment, imparting a somewhat yellowish (ONL = 36-41 mm, DHFL = 28-32 mm) frosted, dingy gray appearance. species ofEliurus characterized by an entirely Skull generally smaller than that ofE. tan- dark, well developed pencil extending over ala and lighter in construction (figs. 13, 1 SB, the distal two-fifths of the tail; skull suggests 1 6B; Appendix 2). Rostrum relatively as long a lighter built, smaller version of E. tanala as E. tanala but tips of nasals narrower. Zy- but subsquamosal fenestra typically open, su- gomatic arches slightly bowed at midsection pernumerary palatal perforations absent or but less flaring than those of E. tanala. Sub- small, and taper of rostrum from nasolacri- squamosal fenestra usually distinct and ovate, mal capsules more pronounced and nasal tips its forward extent exposing some of brain narrower. cavity as well as lateral surface of periotic; DISTRIBUTION: An elongate belt of low to hamular process short but more completely middle elevation rainforest, from Montagne formed than in specimens of E. tanala (fig. d'Ambre in the north to the region of Fara- 18). Bony palate typically perforated with fangana in the south (fig. 1 1). Most geograph- single pair of posterior palatal foramina (fig. ic samples of E. webbi fall between sea level 19); if present, supernumerary palatal open- and 800 m, with the exception of their col- ings appreciably smaller than primary pair. lection at 1500 m on the mountains east of Anterior margin of mesopterygoid fossa ap- Ivohibe. proximately equal with end of third molars. Locality records document the sympatry of Termination of lower incisor alveolus forms E. webbi with E. minor (west ofMaintimbato small capsular projection on dentary, with and west of Vondrozo), E. tanala (NW of weak medial sulcus evident in older animals; Andrambovato), and one of the new species posterior limit of capsular projection about described below (N ofRogez). Where E. web- even with the anterior margin ofthe sigmoid bi and E. tanala have been collected at nearby notch but positioned just below ventral rim places (vicinity ofRanomafana and near Lo- of sigmoid notch (fig. 20D). hariandava), E. webbi is the form that orig- COMPARISONS AND REMARKS: The moder- inated from the localities of lower elevation. ately robust size of E. webbi permits sepa- DESCIPTrION: Penicillate section oftail typ- ration of this species from most other kinds ically conspicuous over distal two-fifths; cau- of Eliurus (Appendix 2). Although E. webbi dal hairs light brown to blackish brown, mon- is larger in cranial size overall, its maxillary ocolored to tip (fig. 12); tuft hairs 10-12 mm toothrow is absolutely and relatively smaller long. Scutellation near base oftail moderately than those of E. majori and E. penicillatus, defined. Fine caudal hairs ofbasal scutes ex- which as a pair differ from it in other pro- tend over 1'/2 annulations. portional features as enumerated in their re- Cover hairs ofdorsum bicolored, proximal spective accounts. Superficial inspection of two-thirds plumbeous gray and distal one- examples of E. webbi may suggest only a third a bright buff, or tricolored with a faintly smaller version of E. tanala with a darkly evident terminal band of black. Buffy band tufted tail; however, many qualitative traits comparatively long and guard hairs more of skin and skull distinguish the two, as de- brownish, conveying a general buffy brown tailed under the preceding discussion of E. dorsal effect. Fur texture soft and fine com- tanala. The consistency of their morpholog- pared to specimens of E. tanala. Dorsal (8- ical divergence, together with the distribu- 10 mm long on midrump) and ventral fur tional evidence, recommends the elevation shorter than in examples of E. tanala. Met- of Ellerman's (1949) webbi to species status. atarsals and phalanges covered with dull white The several locality series that Ellerman hairs. Pinnae relatively large, approximately (1949) assigned to webbi originate from dis- the same as E. myoxinus in absolute size; parate geographic regions collected over a appear naked to unaided eye but lightly cov- wide altitudinal belt. The topotypes from ered with fine reddish brown hairs. Cover Farafangana in the southeastern lowlands are hairs of underparts bicolored, medium gray paler dorsally and ventrally than those from 36 AMERICAN MUSEUM NOVITATES NO. 3087 high (about 1500 m) on the flanks ofIvohibe currence of high-canopy, lowland rainforest Mountain or from the northeastern lowlands (Koechlin, 1972). The few habitat comments near Antongil Bay. The small series from Mt. on specimen tags uniformly identify forest as d'Ambre (elevation unknown) exhibits the the place of capture, and Rand (1932, 1936) brightest pelage appearance among the geo- characterized the localities-for example, W graphic samples available. Creamy white Vondrozo and S Farafangana-where series hairs, monocolored to their bases, cover the of E. webbi have been obtained as tall rain- venter of these specimens from the chin to forest. In the only long-term ecological study groin; only one of five animals displays an of small mammals in lowland rainforest of appreciable expanse ofthe typical basally gray Madagascar, Stephenson (1987) found E. hairs over the midabdomen, which separates webbi2 to inhabitat undisturbed primary for- the white-colored fur ofthe groin and ventral est with a sparse understory and herbaceous forequarters. Still, size and proportions ofthe cover but abundant lianas. Although his live- skin and skull, development and color ofthe trapping grid was laid on the ground, Ste- tail pencil, and basic cranial resemblance sug- phenson observed that individuals ofE. web- gest that all ofthese samples represent a single bi, upon release, scampered toward trees and species. readily ascended lianas draped from a cliff. It is remarkable that such a distinctive and He characterized the species as scansorial. relatively common species as E. webbi, with Webb also noted their capture on tree its wide distribution in rainforests along the branches as well as on the ground. eastern lowlands and coast, escaped notice Field studies should illuminate whether the by the early naturalists in Madagascar. The distributions of E. webbi and E. tanala first examples of E. webbi were apparently broadly correspond to the formation of low- collected in 1929 on a low forested ridge west land rainforest and lower montane rainforest of Vondrozo by the Mission Zoologique (called medium-altitude dense rainforest by Franco-Anglo-Americaine. Regrettably, the Koechlin, 1972), respectively. Around 800 mammalogical findings of the Mission Zool- m, the physiognomy and composition of the ogique Franco-Anglo-Americaine were never forest change; its canopy is lower, harboring synthesized and reported, especially for the a denser herbaceous understory and ground few but highly interesting small mammals that cover, a notable profusion ofmosses on limbs their field teams obtained. Ellerman's (1949) and boulders, and greater abundance of li- formal discovery of webbi, two decades af- anas, epiphytes, and orchids. Although the terwards, was based on the more extensive two overlap in the range of450-850 m, sam- series collected by Cecil Webb over a six-year ples of E. tanala generally occupy a higher period during World War II. In fact, the type elevational belt than those ofE. webbi, a re- locality of webbi, 20 mi S Farafangana, had lationship which may reflect the ecological been visited in 1929 by a team ofthe Mission transition between lowland and lower mon- Zoologique Franco-Anglo-Americaine, which tane rainforest. obtained a single specimen of Nesomys but The record ofE. webbi at 1500 m on Ivo- none of Eliurus. As exemplified by the be- hibe Mountain is a conspicuous exception to lated recognition of E. webbi and elaborated this pattern. Webb's (1954: 263) later elab- by Carleton and Schmidt (1990), specimen- oration of the habitat at this site suggests a based documentation of Madagascar's en- wet montane setting: ".... the undergrowth demic rodents is, as a rule, meager. The na- of the forest was always dripping wet, and ture of the existing nesomyine material in clouds often descended low to clothe every- museums advises the need for improved geographic representation and more careful cen- sus localities. 2 Stephenson (1987) identified the larger of the two of individual Eliurus encountered at his study site as Eliurus sp., the NOTES ON NATURAL HISTORY: Except for smaller one as E. minor. The single voucher (BMNH the 1500-m site on mountains east of Ivo- 1987.108) preserved ofhis unidentified form is referable hibe, most distributional records ofE. webbi to E. webbi and agrees with other examples ofthe species fall between sea level and 800 m. This alti- collected by Webb in the vicinity of Antongil Bay (for tudinal zone broadly coincides with the oc- instance, near Rantabe). 1 994 CARLETON: MADAGASCAR'S RODENTS 37 thing in mist. Mosses and lichens festooned the left hindlimb (femur and tibia-fibula); the the trees and a wonderful variety of ferns left fore- and hindfeet remain on the skin. issued from the crevices ofrocks on the slopes Also contained within the bag is the dried of the steep ravines." Only specimens of E. phallus in a capped vial. The condition ofthe webbi were obtained at this locality, but E. skull is good with the exception of the in- tanala may be expected to occur in the vi- complete right zygomatic arch. cinity. Standard measurements (in mm) from the Juveniles of E. webbi, representing a va- skin tag of the type include head-and-body riety of localities throughout the species' length, 130; tail length, 205; hindfoot length, range, have been collected during the months 33; and ear length, 22. Selected cranial di- of July through December. A count of three mensions recorded by me are: ONL, 38.4; embryos was recorded for a specimen col- ZB, 17.9; IOB, 5.2; PPL, 13.4; LBP, 8.4; LIF, lected in August from south of Farafangana. 4.1; LM1-3, 5.05; and WMI, 1.38. ETYMOLOGY: Described in honor ofthe col- TYPE LOCALITY: 8 km from Fanovana. lector, Cecil S. Webb, who had assembled the DIAGNOSIS: A moderately large (ONL = finest series ofnesomyine rodents then known 37-39 mm, DHFL = 31.5-33 mm) species since the time of Forsyth Major. of Eliurus characterized by bright white un- SPECIMENS EXAMINED: 62 as follows: 2 km derparts sharply delimited from dark dor- NE Andrambovato, 575 and 625 m (USNM sum; tail length relatively longest in the ge- 449266-8); 1 km NW Andrambovato, 875 m nus, about 135 percent of head-and-body (USNM 449269); 3 mi E Andranofotsy, 12 length, with small pencil confined to terminal km NE Maroantsetra, near sea level (BMNH one-fourth of tail; cranium appears delicate 47.1585-8); Antalaha (MNHN 1961.179); for its size, with a narrow rostrum and in- Antalavia, E side Antongil Bay, near sea level terorbit, the zygomatic arches weak and (BMNH 47.1590); 20 mi S Farafangana, 4 bowed little, and the incisive foramina short mi from sea (AMNH 119706-7; BMNH and narrow. 47.1574-84); 12 km E Ifanadiana (MNHN PARATYPES: MCZ 45928 from north ofRo- 1961.216-9); 6 mi E Ivohibe, 5000 ft (BMNH gez; adult, sex indeterminate; skin, skull, and 47.1597-9; USNM 297483); 15 mi E Ivo- partial skeleton; collected by M. Lavauden hibe, 5000 ft (BMNH 47.1594-6); 0.5 km N on 28 May 1929. USNM 341825 from 18 Kianjavato, 300 m (USNM 448991-5); 9 km E Perinet; old adult female; skin and skull; km ESE Kianjavato, 250-500 m (USNM original number 576; collected 28 April 1963 449257-65); 40 km SW Maroantsetra, 10 km by K. Lange. WSW Maintimbato, 450-625 m (BMNH DISTRIBUTION: The three known specimens 1987.108); 40 km NE Maroantsetra, Anko- were collected from closeby localities (Fa- vana, 900 ft (BMNH 47.1589); Mount novana, Perinet, and Rogez), all situated d'Ambre (MNHN 1957.781, 1970.248-9, about 18°50'S, 48035'E in forest due east of 1973.517-8); 8 mi W Rantabe, Antongil Bay, Antananarivo (fig. 10) and from approxi- 500 ft (BMNH 47.1591-3); 13 mi N Rogez, mately 400 to 1000 m. near Lohariandava, 1300 ft (BMNH Sympatry with other Eliurus is currently 47.1624); 20 km W Vondrozo (MNHN undocumented but should be expected be- 1932.3517, 1957.782). cause specimens ofE. minor, E. tanala, and E. webbi are recorded from nearby localities. For example, K. Lange, in 1963, obtained Eliurus petteri, new species specimens of E. tanala in disturbed rainfor- Figures 12, 14, 1SA, 16A, 20E est at distances 1, 2, and 13 km along the HOLOTYPE: MNHN 1961.177; young adult road east of Perinet (= Andasibe) and the male; skin and skull; original number 174; single example of E. petteri from the place collected 6 October 1956 by Jean-Jaques Pet- located 18 km east. ter. DESCRIPrION: Terminal tuft weakly devel- In a plastic bag attached to the skin are the oped, limited to distal 25 to 30 percent oftail intact, articulated elements of the left fore- length; hairs of tuft light brown to grayish limb (scapula, humerus, and radius-ulna) and brown, 8-10 mm long. Long proximal sec- 38 AMERICAN MUSEUM NOVITATES NO. 3087 tion oftail appears naked macroscopically for E. minor. Posterior palatal foramina formed approximately two-thirds to three-quarters as a single pair of small openings. Anterior of its length (fig. 12). Scutellation fine, scale margin of mesopterygoid fossa about equal hairs short (about one annulation long) and with the ends of the third molars. None of inconspicuous. Caudal epidermis dusky, ei- the three skulls possesses any trace of the ther monocolored or with white splotches on bony strut of the alisphenoid that separates proximal two-thirds of ventrum. the masticatory-buccinator foramen and fo- Cover hairs of dorsum tricolored-basal ramen ovale accessorius as seen in other spe- two-thirds light gray, middle band pale buff, cies. Subsquamosal fenestra present in all and terminal band dark brown to blackish. three specimens, moderately large, about as Middorsum exhibits denser concentration of in E. webbi, and revealing the inner braincase hairs with blackish tips and/or hairs with lon- as well as the petrous portion of the periotic; ger terminal bands. Tone muted, general col- hamular process of squamosal thus well de- or grayish brown but variation observable fined. Tympanic bullae appear relatively the among three known specimens: type more smallest in the genus, only slightly larger in charcoal-gray, especially middorsally where absolute dimensions than in specimens ofE. a broad but indistinct dark band is suggested; minor. MCZ 45928 with more brownish tones, par- Upper and lower incisors relatively thin in ticularly on the head and flanks, darker on width and depth, hardly more robust than middle back; USNM 341825 an intermediate those of E. minor. Enamel face of upper in- gray-brown. Dark eye-rings present in two of cisors yellow to pale orange. Alveolus oflow- three specimens. Guard hairs dark but rela- er incisors short, terminating at the level of tively inconspicuous, only slightly longer than the coronoid process and low on the ascend- cover fur. Pelage texture fine and soft, some- ing ramus (fig. 20E), without any capsular what sleek in appearance, 8-10 mm long on projection even in the oldest specimen. Mo- midrump. Distinct narrow dusky streak ex- lar rows as long relative to cranial size as in tends over dorsum of tarsus and metatarsus; other Eliurus except E. majori and E. peni- remainder of metatarsus and digits covered cillatus. with white hairs. Tops of forefeet wholly COMPARISONS AND REMARKS: Examples of white, dark dorsal pelage ending abruptly at E. petteri recall a diminutive version of E. carpus. Cover hairs of underparts monoco- webbi at first inspection. Closer examination, lored white in all three specimens, giving the however, reveals many features that contrib- entire venter, including the inner surfaces of ute to the singular differentiation and the fore- and hindlimbs, a bright white ap- straightforward identification of this form pearance from the chin to groin that contrasts with respect to other members of the genus. sharply with the darkly colored dorsum. Its white venter, whose purity and brightness Mystacial vibrissae about 50-60 mm long, are exaggerated by contrast to the somber- extending well past base of pinnae when ap- colored dorsum, is unmatched by any other pressed to skin. Pinnae pale dusky, in gross species ofEliurus. Aside from the sharp dor- examination devoid of fur but clothed exter- sal-ventral contrast, the sleek texture of its nally with short brown hairs and internally dorsal pelage and the modest development with fine white ones. ofa monocolored tuft on a relatively long tail Skull only slightly smaller than that of E. can alone serve to distinguish E. petteri from webbi but conformation gracile (figs. 14, 1 5A, its similarly sized congeners, E. tanala and 1 6A), suggesting examples of E. minor. Zy- E. webbi. gomatic arches weakly developed, particu- The cranium ofE. petteri is remarkable for larly over their middle span, little expanded its light and delicate appearance despite a size laterally. Interorbital region hourglass-shaped, that approaches smaller individuals of E. lacking any definition of suprorbital shelves webbi (figs. 15, 16). Characteristics that con- and ridges, and braincase smooth and round- fer the impression ofdelicate proportions ined, less elongate compared to other Eliurus clude the slender incisors, thin zygomatic except E. minor. Incisive foramina narrow arches, smoothly rounded braincase, and tiny and short, approximately the same size as in auditory bullae. Specimens of E. petteri ap- 1 994 CARLETON: MADAGASCAR'S RODENTS 39 pear little larger than examples of E. minor in good condition except the left pterygoid in certain cranial dimensions, notably those process and rim of the left auditory bulla of the incisive foramina, which are propor- damaged. The collector's name appears only tionately the smallest in the genus. The al- on a secondary tag that was clearly attached veoli of the lower incisors in E. petteri are later, perhaps when cataloged in 1981, and also extreme within Eliurus for their short- is qualified by a question mark in parenthe- ness and the lack of an incisive capsule on ses. the lateral surface ofthe dentary (fig. 20E). If TYPE LOCALITY: Hiaraka, near Maroantse- the absence ofthe alisphenoid strut holds true tra, 850 m altitude. MacPhee (1987) located for larger samples of the new species, then Hiaraka as 40 km NW Maroantsetra (Toa- this condition too would mark E. petteri as masina Province, about 15°10'S/49°30'E). unique compared to other Eliurus in which DIAGNOSIS: A large (ONL = 42-44 mm, the structure is consistently present. DHFL = 33-34 mm) species of Eliurus that The recorded length of205 mm for the tail resembles a robust version of E. tanala ex- vertebrae ofthe holotype (MNHN 1961.177) cept with the tail brush completely dark to seems inordinately long for its appearance the tip; skull stoutly constructed, especially relative to the head-and-body of the skin. as seen in its broader interorbit, braincase, Tail length on the dry specimen measures 185 and expanse of zygomatic arches. mm, which is the value used for the calcu- PARATYPE: BMNH 47.1623 from 13 mi N lation of its proportional length. Rogez, near Lohariandava, 1300 ft altitude; NOTES ON NATURAL HISTORY: Notations adult male; skin and skull (occiput broken); on skin tags indicate that the type specimen original number P.70; collected 10 December was obtained "en foret vierge" and USNM 1939 by Cecil S. Webb. 341825 in "Rainforest. In an area with large DISTRIBUTION: The two widely separated granite outcrops and tangled undergrowth. localities suggest that the species should be Hillside habitat." No additional natural his- sought in low-to-intermediate elevation rain- tory information is available. forest of northeastern Madagascar (fig. 10). ETYMOLOGY: The species name honors the A specimen of E. minor is also recorded substantial contributions of Dr. Francis Pet- from the type locality, and the paratype was ter, Museum National d'Histoire Naturelle, collected together with a much smaller Eli- to our sytematic knowledge of Madagascar's urus that Ijudge to be an example ofE. webbi. endemic rodents. His research has uncovered DESCRIPTION: Caudal pilosity moderately the existence (1959, 1962) ofnew forms (Ma- developed, extending about one-third of tail, crotarsomys ingens and Brachytarsomys al- tuft hairs 9-11 mm long. Hairs dark to tip of bicauda villosa) and addressed the origin and tail on the paratype and apparently so on the relationships of Nesomyinae within the ra- holotype, though its tip is missing; pencil hairs diation of Muroidea (1961, 1972, 1990). colored pale brown to dusky. Scutellation grossly apparent over basal two-thirds of tail and relatively coarsely defined; caudal epi- Eliurus ellermani, new species dermis darkly pigmented on dorsum and Figures 14, 15D, 16D venter; hairs near base of tail about 1 l/3 an- HOLOTYPE: MNHN 1981.871; adult male; nulations long. skin and skull; original number 15; collected Dorsal pelage drab, coloration much as in January 1968 by R. Albignac. examples of E. webbi but texture harsher. Standard measurements (in mm) recorded Cover hairs of dorsum mostly tricolored- on the skin tag ofthe type include head-and- proximal three-quarters plumbeous gray, and body length, 152; tail length, 177; hindfoot distal one-quarter pale buff, with or without length, 35; and ear length, 20. Selected cranial a very short dark tip. Length of buffy band dimensions measured by me are: ONL, 43.8; appears greater on sides and flanks, which are ZB, 18.8; IOB, 6.3; PPL, 15.5; LBP, 9.2; LIF, lighter than the middorsum. Guard hairs nu- 5.8; LM1-3, 5.82; and WM1, 1.61. merous and shiny black. Overall dorsal effect Skin with very tip oftail missing and patch- a dark grayish brown. Ventral cover hairs es of fur lost on the belly and left flank. Skull monocolored a dingy creamy buff from the 40 AMERICAN MUSEUM NOVITATES NO. 3087 chin to groin on the holotype, but some basal with the British Museum (Natural History), gray banding evident on the paratype to give London. Among his many systematic com- a darker tone. Dark eye-rings present, more pendia of mammals, Ellerman's scientific conspicuously defined on the paratype. reputation is linked principally to his three- Skull stout and heavy in build, suggesting volume treatise on The Families and Genera a robust version ofE. tanala in most features of Living Rodents (1940, 1941, 1949). His and proportions (figs. 14, 1 5D, 1 6D). Incisors contributions to our understanding of neso- wide and deep front to back, enamel pigment myine rodents remain little appreciated; of uppers a strongly saturated orange. Both however, the last published and least cited crania with supernumerary palatal perfora- third volume of Families and Genera con- tions, those ofthe type small and those ofthe tains an appendix on the material collected paratype about equal in size to the posterior by Cecil Webb, together with a summary of palatal foramina themselves. Subsquamosal the known nesomyine taxa and description fenestra expressed on the type as a shallow of the distinctive form Eliurus myoxinus indentation, not exposing any of the brain webbi. His chapter was the most valuable cavity, and on the paratype as a distinct notch, synopsis of the group published to that date forming a short, broad hamular process. Ter- and established the species-level taxonomy mination of the lower incisors marked by a recognized today. Moreover, Ellerman (1940, distinct capsular projection situated high on 1941) promulgated the most radical classi- the ascending ramus, below the middle ofthe ficatory treatment yet of Madagascar's ro- sigmoid notch. dents, in disputing their common ancestry COMPARISONS AND REMARKS: As observed and instead allocating the seven genera among in its large skull and hindfoot, this species is five subfamilies of a broadly defined Family at the upper limits of size so far recorded for Muridae. His arguments for departing from the genus. Only the very largest specimens of the traditional classification have yet to be E. tanala match the two of E. ellermani in seriously addressed and convincingly refut- some cranial dimensions (Appendix 2; it ed. should be remembered that the ONL of the paratype is some value greater than 42.6 mm since its occiput is broken). The skin of E. INTERSPECIFIC RELATIONSHIPS ellermani, on the other hand, more strongly Interpretation of phylogenetic affinities resembles examples ofE. webbi in dorsal and among the species of Eliurus must be con- ventral pelage color and in the dark, mono- sidered preliminary at this stage, as it is lim- colored tail tuft. One might suspect that the ited to morphological data derived from the skull from a tanala and the skin of a webbi skin and skull as summarized by morpho- had been inadvertently associated were it not metric analyses and by resemblances in a few for the combination of these cranial and pel- discrete traits. age traits in two specimens, obtained by dif- Little sense of specific relationships can be ferent collectors from distant localities at sep- gleaned from the early descriptive literature, arate times. The correspondence of features which contains scant comparative evalua- exhibited by both of these examples seems tions. Ellerman (1941), however, first stressed too compelling for me to twice dismiss their general size as a fundamental criterion ofkin- uniqueness to an error of specimen process- ship within the genus by noting the markedly ing. Further material is needed to ascertain smaller dimensions of E. minor in contrast the typical morphological condition for cer- to all other species then known (majori, tain cranial foramina that differ slightly in myoxinus, penicillatus, and tanala). In 1949, the two available specimens. he formalized this viewpoint and relegated NOTES ON NATURAL HISTORY: No ecolog- the larger-bodied taxa (majori, penicillatus, ical or reproductive information is associated tanala, and webbi) to subspecies of a poly- with either of the known specimens. typic E. myoxinus, which as a result consti- ETYMOLOGY: The species is named in rec- tuted the lone congener to the monotypic E. ognition of Sir John Reeves Ellerman, one- minor. His formal classification of Eliurus time shipping magnate and research associate thus conveys, ignoring differences in assign- 1994 CARLETON: MADAGASCAR'S RODENTS 41

A LL TA 11 TA 10 TA12 MY 6 MY 7 PT 18 WE13 WE1 4 WE16 WE15 WE17 PN 8 MA 9 Ml 1 Ml 3 MI 2 MI 5 MI 4 .25 .20 .15 .10 .05 0.00 Euclidean D

B EL 19 TA 10 TA 12 TA 11 WE17 WE1 5 WE16 WE14 WE13 PT 18 MY 6 MY 7 Ml 1 MI 5 Ml 4 Ml 2 rmhIzzIzII PNMl 83 MA 9 .8 .7 .6 .5 .4 .3 .2 .1 0.0 1 -r Fig. 21. UPGMA clustering of log-transformed sample means for the 19 OTUs of Eliurus identified in the Materials and Methods, using both a Euclidean distance coefficient (A) and the Pearson correlation coefficient (B). Species abbreviations: EL, E. ellermani; MA, E. majori; MI, E. minor; MY, E. myoxinus; PN, E. penicillatus; PT, E. petteri; TA, E. tanala; WE, E. webbi. 42 AMERICAN MUSEUM NOVITATES NO. 3087

6 I I I I I

01- EL

-2

-4

-6

-8

-10 I I IXI s I I -12 -10 -8 -6 -4 -2 0 2 4 6 8 cv I Fig. 22. Plots offirst two canonical variates extracted from discriminant function analysis performed on eight species of Eliurus and using all specimens with intact skulls (N = 128). Polygons enclose maximal dispersion of individual specimen scores around group-centroids for each of eight species (see tables 3 and 4). Species abbreviations and sample sizes: EL, E. ellermani (N = 1); MA, E. majori (N = 4); MI, E. minor (N = 28); MY, E. myoxinus (N = 9); PN, E. penicillatus (N = 12); PT, E. petteri (N = 3); TA, E. tanala (N = 31); WE, E. webbi (N = 40). ment of taxonomic rank, only a simple di- trast, use of a correlation measure, more sen- chotomy determined principally by size. sitive to proportional similarities (for example, see Minkoff, 1965), reveals the strong MORPHOMETRIC COMPARISONS separation of E. majori and E. penicillatus from other Eliurus (fig. 21B). Using a cor- Results ofthe multivariate analyses do not relation coefficient, the cluster of E. minor fully sustain Ellerman's appraisal of mor- OTUs still remains well defined, as does that phological divergence among the described of E. myoxinus, but examples of E. webbi, forms and instead offer alternative estimates E. tanala, and E. ellermani are somewhat of their interrelationship. Pair-wise associa- interspersed, reflecting their fundamental re- tion of OTUs based on a distance coefficient semblance in craniodental proportions. As corresponds to the specific groupings ad- noted in the appropriate species accounts, vanced herein, and the first bifurcation does justification for the specific status of these impart a simple division ofsmall versus large three forms draws from qualitative character forms (fig. 21 A) in general accordance with differences as well as distributional infor- Ellerman's (1941, 1949) taxonomy. In con- mation. 1 994 CARLETON: MADAGASCAR'S RODENTS 43

TABLE 3 TABLE 4 Results of Discriminant Function Analysis Matrix of Mahalanobis Distances Between Cen- (Performed on 18 cranial measurements of in- troids of Species Samples of Eliurus (see fig. 22) tact specimens of Eliurus [N = 128]; see fig. 22.) Species abbreviations: MA = E. majori; PN = E. penicillatus; MY = E. myoxinus; MI = E. mi- Correlations nor; PT = E. petteri; WE = E. webbi; TA = E. Variable CV I CV II F (group)* tanala; EL = E. ellermani. ONL 0.93 0.27 156.1 Species ZB 0.89 0.89 65.2 PN BBC 0.90 0.22 89.7 MY MI PT WE TA EL IOB 0.77 0.41 48.7 MA 7.6 11.8 15.6 14.1 10.7 9.7 9.1 LR 0.90 0.29 118.3 PN - 9.6 13.9 11.9 9.2 9.8 10.3 WR 0.83 0.07 36.0 MY - 10.5 7.8 6.2 8.3 10.1 PPL 0.87 0.26 70.9 MI - 10.4 11.5 14.7 15.8 LBP 0.84 0.47 120.5 PT - 7.7 10.2 11.2 LIF 0.84 -0.17 48.9 WE - 5.9 7.5 LD 0.87 0.38 109.9 TA - 5.0 LM1-3 0.93 -0.31 228.8 WM1 0.91 -0.24 102.2 WIF 0.56 -0.39 20.0 BMIs 0.95 0.04 133.9 erally plague an enhanced phylogenetic un- PPB 0.83 -0.17 47.3 derstanding of muroid rodents at the species DAB 0.83 -0.03 73.0 level. These are: 1) the paucity ofphenotypic WZP 0.82 0.40 67.3 variation that is expressed as discrete alter- BOC 0.93 0.17 109.0 natives and that lends itselfto clear character- * = All univariate F tests significant at P < .001. state definitions; and 2) the lack of strongly corroborated, higher-level phylogenies within Muroidea sufficient to allow confident In like manner, three phenetic clusters are identification of sister taxa and thereby to readily apparent in discriminant function illuminate polarity interpretations among analysis. One is composed of examples ofE. what few qualitative characters can be mean- minor and another of larger species (E. el- ingfully considered. lermani, E. myoxinus, E. petteri, E. tanala, Consideration of the second factor point- and E. webbi), a separation consistent with edly illustrates our lack of knowledge with Ellerman's (1949) revision. The third group regard to the genus under current study. Winge also represents larger-bodied taxa (E. majori (1941), for example, arranged Gymnuromys and E. penicillatus) that are as differentiated as the nearest living relative ofEliurus, both in character space from the set of other large classified within the group Rhizomyes, in species as is E. minor (fig. 22). The hiatus which he included the other Malagasy ro- delimiting specimens of E. majori and E. dents, African mole rats (Tachyoryctes), and penicillatus issues from proportional con- Asian bamboo rats (Rhizomys). Ellerman trasts such as their relatively robust molar (1940, 1941), on the other hand, placed Eli- rows, long and wide incisive foramina, a short urus as the lone genus of the group Eliuri bony palate, and narrow interorbital region within the subfamily Murinae and dispersed (table 3). Average Mahalanobis distances de- the other Malagasy genera among the Cri- rived among the 8 species samples ofEliurus cetinae, Gymnuromyinae, Microtinae, and (table 4) fall well within the range or exceed Tachyoryctinae. Both authors advocated a those recorded for other congeneric species broadly inclusive definition of the Family of muroid rodents (Voss and Marcus, 1992). Muridae. Their dramatically contrasting viewpoints underscore the more fundamental and still unsettled phylogenetic issue of PHYLETIC INFERENCES the monophyly ofthe subfamily Nesomyinae Any attempt to marshall cladistic analyses (see Carleton and Musser, 1984, and Petter, of relationship among species of Eliurus is 1990, for reviews), resolution of which is far hindered by the same two factors which gen- beyond the scope of this study. Notwith- 44 AMERICAN MUSEUM NOVITATES NO. 3087

TABLE 5 Matrix of Character States Among Eight Species of Eliurus (see text and fig. 23) Species abbreviations: MA = E. majori; PN = E. penicillatus; MY = E. myoxinus; MI = E. minor; PT = E. petteri; WE = E. webbi; TA = E. tanala; EL = E. ellermani; OG = composite outgroup. Species Character MA PN MY MI PT WE TA EL OG 1. Pelage contrast c c a a b a a a ? 2. Fur texture b b a a a a a a ? 3. Tail penicillation a a c b b b b b a 4. Tail color a b a a a a b a a 5. Zygomatic notch a a b b b b b b a 6. Incisive foramina c c b b a b b b ? 7. Palatal foramina a a a b a a b b a 8. Mesopterygoid fossa a a b b b b b b a 9. Molar rows a a b b b b b b a 10. Third molars a a b b b b b b a 11. Subsquamosal foramina a a a a a a b b a 12. Alisphenoid strut a a a a b a a a a 13. Basicranial flexion a a a b a a a a a 14. Lower incisor b b b b a b c c ? 15. Mandibular shape b b a a a a a a a ? = Character state coded as unknown. standing the evolutionary uncertainties ex- rigorous evaluations of kinship among spe- pressed at the ranks of tribe and subfamily, cies of Eliurus. the numerous and distinctive craniodental Characters: A total of 15 qualitative char- and external features shared by the eight acters, as described below and listed in table known species ofEliurus, whether contrasted 5, was distilled from the foregoing morpho- to other nesomyines or to any other muroid, logical comparisons. The alphabetic order of convince me that the monophyly ofthe genus states within most characters represents the is a reasonable hypothesis at this stage of in- hypothesized sequence of primitive-derived quiry. changes, in which all transformations are lin- Without a firm phylogenetic framework, ear (from a to b, or from a to b to c); the some guidance on transformation polarities ancestral state of a few was treated as un- may be gleaned from character data used in known. This character set predicts a mini- investigations of other radiations of Muroi- mum-length network or tree of 19 steps. Sev- dea (for example, Carleton, 1980; Hershkov- eral of the character states are simple itz, 1962; Musser and Newcomb, 1983; Voss, verbalizations of the shape differences un- 1988), and this is the course adopted here. covered in multivariate analyses; others in- The outgroup traits thus identified (table 5) volve discrete trait variation that is not easily and used to root the cladograms produced in described by conventional landmark mea- the PAUP analyses are a composite of the surements. character polarity arguments contained in the Character 1. Dorsal-ventral pelage con- aforementioned studies of Muroidea. Deci- trast: (a) moderate-venter grayish, dorsum sions on the ancestral-derived condition of dark brown to blackish; (b) strong-venter character attributes, however, depend much white and dorsum dark, lateral demarcation upon the taxonomic level of one's analysis; sharply defined; (c) weak-venter colored therefore, polarity hypotheses drawn from the about as dark as dorsum, little lateral de- perspective of the superfamily may obscure marcation. local instances ofcharacter-state reversals, for Remarks: Moderately pronounced coun- example at the generic and specific levels. tershading, with a lighter gray to grayish-white The weakness of my approach is here ac- venter, is commonplace among species of cepted as an exploratory exercise to spur more Muroidea and may be plausibly assumed as 1 994 CARLETON: MADAGASCAR'S RODENTS 45 the ancestral state. Voss (1988), however, in- Eliurus, since the incisive foramina in the terpreted a darkly colored venter as primitive genus are short compared to those of many within ichthyomyine rodents (Sigmodontin- species of Muroidea. Assignment of a ple- ae). Consideration ofeither state as ancestral siomorphic state is problematic in view of does not undermine the fundamental rela- the common occurrence ofspecies with short tionships predicted below, but in view of the or long foramina within the superfamily. uncertainty, the character was treated as un- Wahlert (1985) viewed the elongate foramina known in the outgroup. of muroids, whose aperture traverses equal Character 2. Fur texture: (a) normal, harsh- lengths of the premaxillary and maxillary er; (b) wooly and fine. bones, as derived within Rodentia, and Mus- Character 3. Development of tail penicil- ser and Newcomb (1983) scored longer in- lation: (a) little pronounced; (b) moderate; (c) cisive foramina as derived within Malaysian conspicuously long and bushy. murines. Quay (1954), however, provided Remarks: See discussion under next char- persuasive evidence for reduction in size of acter. the incisive foramina in certain Arvicolinae. Character 4. Color of tail tuft: (a) dark to The outgroup condition was coded as inde- tip; (b) white tip. terminate. Remarks: Tails with contradistinctively Character 7. Posterior palatal foramina: (a) colored tips, usually bright white, and with single pair of foramina; (b) supernumerary distally elongated hairs have evolved in a foramina present, posterior to principal pair number of rodent groups, most notably the and sometimes conjoined to form elongate stylized "banner" tails found in many Old vacuities. World jerboas (Dipodidae) and New World Remarks: The condition observed in most kangaroo rats (Heteromyidae). The occur- Eliurus is typical of muroids in general, and rence of white-tipped, conspicuously peni- the postulated evolutionary sequence follows cillate tails is seemingly rarer within Muri- Carleton (1980), who encountered unusually dae, although they are known in other genera long posterior palatal foramina only among of broad-footed, arboreal murids like Chi- Gerbillinae. Samples of E. minor are poly- ropodomys and Margaretamys (Musser, 1979, morphic for this character, but the derived 1981). The choice of the derived state seems state characterizes most individuals exam- clear as does the probable independent ac- ined. quisition of white caudal tips within Muri- Character 8. Forward extent of mesoptery- dae. Even within Eliurus, strong evidence goid fossa: (a) penetrates slightly between up- supports convergent evolution ofthe plumed per third molars; (b) terminates level with white tips exhibited by E. penicillatus and E. posterior border of third molars. tanala (see below). Remarks: The contrast between species of Character 5. Relative depth of zygomatic Eliurus does not match that typical of the notch: (a) shallow, zygomatic plate narrow; short and long bony palates noted by Hersh- (b) moderate, zygomatic plate relatively kovitz (1962) for various groups of South broader. American sigmodontines. The difference is Remarks: The distinction between E. ma- nonetheless consistent, and the direction of jori-penicillatus and other Eliurus in expres- change agrees with the interpretations pre- sion of a zygomatic notch is slight compared sented in other studies of mu- to the conspicuously deep notches and broad phylogenetic plates developed in some muroids (for ex- roids (Carleton, 1980; Hershkovitz, 1962; ample, Gerbillinae). The direction ofchange, Musser and Newcomb, 1983). however, is consistent with previous inter- Character 9. Relative length of molar rows: pretations of variation in this character in (a) long (about 16-17% of ONL); (b) short other muroids (Carleton, 1980; Carleton and (about 13-14% of ONL). Musser, 1989; Musser and Heaney, 1992). Remarks: The relatively and absolutely Character 6. Relative length of incisive fo- longer toothrows observed in E. majori and ramina: (a) short; (b) moderate; (c) long. E. penicillatus are hypothesized to be the ple- Remarks: The above descriptions of fo- siomorphic state. raminal length are meaningful only within Character 10. Relative length of upper third 46 AMERICAN MUSEUM NOVITATES NO. 3087 molars: (a) subequal to M2; (b) smaller than Eliurus, this character too was eliminated M2. from construction of evolutionary trees. Remarks: Reduction in size ofthe M3 con- Character 14. Development of lower inci- curs with the polarity conclusions of other sor: (a) alveolus short, ending anterior to sig- studies but is a trend that has obviously moid notch, without lateral capsular projec- evolved in parallel within several lines of tion; (b) alveolus moderate in length, ending Muroidea (Carleton, 1980; Musser and New- below the coronoid process and forming a comb, 1983; Voss, 1988). Characters 8, 9, slight capsular projection; (c) alveolus long, and 10 could plausibly be viewed as redun- ending below the rim of the sigmoid notch dant descriptions ofa single anatomical com- and forming a distinct capsular projection. plex; that is, reduction in size of the third Remarks: The morphology described un- molars achieves a relatively shorter molar row der (b) corresponds to the common condition overall and imparts a correspondingly longer observed within Muroidea; however, the for- appearance to the bony palate. mation of a distinct capsular projection or Character 11. Development of subsqua- knob (c) occurs frequently as well and within mosal fenestra: (a) present, usually revealing many subfamilies, whereas that identified as brain cavity; (b) absent, or small forming a (a), here noted for only E. petteri, is rarer. I shallow notch and not revealing the interior cannot offer any compelling rationale for the of the braincase in lateral view. polarity of this character, and it was entered Remarks: While noting that subsquamosal as an unknown in the hypothetical outgroup fenestrae are present in most representatives (table 5). of the Gerbillinae, Microtinae, Old World Character 15. Mandibular conformation: cricetines, South American cricetines, and (a) slender appearance, ramus low slung; (b) neotomine-peromyscines, I earlier (1980: 44) stocky appearance, high ascending ramus and persuaded myself that their absence repre- arching coronoid process. sented the ancestral state. Voss (1988) ques- Remarks: The state tentatively recognized tioned this polarity decision and reopened as derived suggests the remodeling of the the larger issue ofthe presumed homology of mandible described in the evolution of the this opening with the squamosomastoid fo- Arvicolinae from generalized cricetids (Re- ramen found in other rodents (see Voss, 1988: penning, 1968), although none of the asso- 295, and Wahlert, 1985, for discussions). In ciated dental specializations of arvicolines light of this uncertainty, my character-state pertains to species of Eliurus. transition straightforwardly recognizes the Results using PAUP: Treatment of all 15 wider taxonomic distribution of an open fe- characters as unordered produced a rootless nestra as indicative of primitiveness. network of 20 steps (fig. 23A). The large hi- Character 12. Occurrence of alisphenoid atus separating E. majori and E. penicillatus strut: (a) present; (b) absent. from other Eliurus derives from the many Remarks: Loss ofthe alisphenoid strut has proportional differences oftheir crania (char- occurred in several muroid groups (Carleton, acter states Sa, 6c, 8a, 1 Sb) and dentition (9a, 1980; Musser and Newcomb, 1983). The de- 10a), as well as their distinctive pelage (1c, rived state was recorded only for the three 2b, 3a). The next greatest distance generated examples ofE. petteri, and the character was over all characters along the network reflects omitted from the phylogenetic analyses. the several unique traits (lb, 6a, 12b, 14a) Character 13. Degree of basicranial flex- observed in the new species E. petteri. Pos- ion: (a) weakly pronounced, foramen mag- session of a white terminal pencil (4b) by E. num oriented mostly caudad; (b)strongly pro- tanala accounts for the single-step difference nounced, foramen magnum oriented between it and E. ellermani, both of which posteroventrally. otherwise share similarities in their palatal Remarks: The strongly arched cranial vault morphology (7b), patency of the subsqua- of E. minor resembles the contrast noted by mosal fenestra (1 lb), and development ofthe Carleton and Musser (1989) between certain lower incisor (1 4c). The divergence ofE. mi- oryzomyines and that they coded as apo- nor from large-bodied forms like E. myoxi- morphic. Recorded for only one species of nus and E. webbi, considered on the basis of 1 994 CARLETON: MADAGASCAR'S RODENTS 47

A MY

PN MA Ml EL TA WE

B EL 4b

Ml / 14C WE 1 lb MA MY 7b 4b 10b 15b 9b 6c 8b 2b 5b 1C \og 3b Fig. 23. Affinity among species of Eliurus based on 15 qualitative characters (see text and table 5): A, minimum-length network (L = 20) with all multistate characters treated as unordered; B, strict consensus summary of phylogenetic relationships based on 15 most parsimonious trees (L = 18, ci = 0.94). Character state changes depicted are common to all 15 most parsimonious trees; single homo- plasious transition (4b) is underlined; autapomorphies are not indicated for E. myoxinus (3c) and E. petteri (lb, 6a, 14a). Species abbreviations: EL, E. ellermani; MA, E. majori; MI, E. minor; MY, E. myoxinus; PN, E. penicillatus; PT, E. petteri; TA, E. tanala; WE, E. webbi.

qualitative features unrelated (presumably) parsimonious trees (fig. 23B; L = 18, ci = to size, is unremarkable in contrast to the 0.94). The variation in the 15 trees involved results disclosed in the various multivariate the branching patterns predicted around the analyses of craniodental data. node subtending E. myoxinus, E. petteri, E. Generation of evolutionary trees using the webbi, and the E. minor-ellermani-tanala 13 cladistically informative characters (nos. clade. Moreover, these variations all in- 12 and 13 were omitted) produced 15 equally volved zero-length branches that portrayed 48 AMERICAN MUSEUM NOVITATES NO. 3087 the theoretical cladistic possibilities around NATURAL HISTORY INFORMATION that node, and no distance separated the hypothesized outgroup from the basal node. A In a 1985 IUCN survey ofAfrican rodents strict consensus tree was computed to sum- that may warrant conservation concern, marize the branching topography and char- Schlitter then characterized our systematic acter state transitions common to the 15 most and biological understanding of most neso- parsimonious trees (fig. 23B). myine species, including Eliurus myoxinus The cladistic information contained in the (sensu Ellerman, 1949) and E. minor, as "In- discrete character data is insufficient for sufficiently Known." Knowledge of the ecol- wholly resolving relationships among the ogy, diet, and reproduction of Eliurus has eight species of Eliurus, but certain patterns improved little and remains fragmentary at of descent do emerge. Eliurus majori and E. best. Available information derives mostly penicillatus are predicted to share a common from anecdotal sources such as specimen tags ancestor that differentiated early relative to and fieldnotes, not from explicitly designed the radiation ofother species ofEliurus. These field investigations. What is known, or plau- two species possess several characters that sibly suspected, may be summarized as fol- can be credibly posited as plesiomorphic- lows. such as the narrow zygomatic plate and in- Species ofEliurus are uniformly associated distinct notch (5a), shorter bony palate (8a), with arborescent habitats, most species in hu- robust third molars (1 Oa)-and two others mid evergreen forests along the eastern low- that could be so interpreted appropos of cer- lands and contiguous escarpment, but one (E. tain polarity arguments-like the indistinct myoxinus) in dry deciduous forest and scrub dorsal-ventral countershading (1 c) and wider formations in the west and southwest. The and longer incisive foramina (6c). The phy- fidelity ofspecies to given floristic formations logenetic analysis nonetheless treated the lat- and nature of preferred microhabitats are ter traits as derived for the majori-penicil- largely unknown. Stephenson (1987) dem- latus clade, given the assignment ofunknown onstrated the importance ofdense viny growth states to the outgroup and application ofpar- and a sparse understory in predicting the simony criteria. presence ofE. minor and E. webbi in lowland The remaining Eliurus species, including rainforest. In eastern forest, limited distri- E. minor, display apomorphic features for butional evidence, notably for E. tanala and many of these same characters (3b, Sb, 8b, E. webbi, suggests altitudinal stratification 9b, 10b) and form a well-supported mono- approximately coincident with the ecotone phyletic group. Relationships within this from lowland to montane rainforest. Eliurus complex are less clear, particulary with regard minor, on the other hand, ranges widely in to E. myoxinus, E. petteri, and E. webbi. In altitude and occupies both types offorest, but surprising contrast to Ellerman's (1949) clas- the consanguinity ofpopulations allocated to sification and some of the morphometric this nominal species needs verification. evaluations, E. minor is represented as more Notes on trap placement substantiate high- closely related to the largest species, E. tanala ly developed scansorial abilities, which con- and E. ellermani, based on its typical pos- form predictably to the broad-footed, long- session of supernumerary palatine foramina tailed physiognomy characteristic of the and a more fenestrated palate (7b). My own genus. Whether the tufted-tailed rats ofMad- preconception of kinship patterns had fa- agascar utilize upper portions of the forest vored a sister-group relationship ofE. webbi canopy has yet to be explored. "Arboreal" to E. tanala-ellermani, a conjecture shaped sampling using conventional trapping meth- by the phenetic analyses but not borne out ods, which undoubtedly accounts for most by the cladistic evaluation of the discrete nesomyines in museum collections, is limited characters. Recourse to other kinds of sys- to reachable branches and vines, usually 2 m tematic data is clearly required to test and or less in height. In lowland tropical rainfor- refine the preliminary patterns of phenetic est in Brazil, for example, Malcolm (1990) divergence and phylogenetic relationship de- revealed greater activity levels and popula- veloped herein. tion densities for certain muroid rodents 1994 CARLETON: MADAGASCAR'S RODENTS 49

(Oecomys and Rhipidomys) in upper canopy alveoli of E. petteri raise questions about its (15 m) than on the ground where they are diet compared to foodstuffs ingested by other sometimes captured. The bodily conforma- Eliurus. The length of the lower incisor al- tion of these sigmodontine genera recalls, in veolus and size ofthe capsular projection pre- a general way, that of Eliurus. sumably reflect the degree of wear on the in- The trophic niche ofEliurus similarly lacks cisor tips and may correspond to the relatively detailed substantiation. Stephenson (1987) indurate nature ofseeds or insects consumed. noted that in captivity both E. webbi and E. These incisor and mandibular differences are minor relished coconut, but whether their not simply due to size-allometry factors, for predilection under this circumstance conveys relative length of the lower incisor and cor- much about their regular diet needs docu- responding protrusion ofthe capsular process mentation. Dietary studies would be highly are well expressed in the smaller-bodied E. interesting in light of the moderately devel- minor. oped hypsodonty and laminate dentition that Anecdotal observations by collectors sug- characterize the genus. Such dental adapta- gest that some species, notably E. myoxinus, tions contrast with the low-crowned, cuspi- nest in tree-holes, but the generality of this date molars found in other scansorial or ar- habit for the genus needs careful substanti- boreal muroids with a bodily form like that ation in the field. Litter size in Eliurus, based ofEliurus, for example, the Neotropical gen- only on six records, is apparently small, rang- era Oecomys and Rhipidomys. Crown height ing from one to three young. These records in Eliurus instead resembles the condition and other kinds of evidence (testes descend- observed in species ofHolochilus, some Phyl- ed, lactation, juveniles present) document lotis, or some Otomys, all of which are ter- some breeding activity at least over the latter restrial forms inhabiting savanna-grassland half of the year (July-December). Most field biomes and whose herbivory is better estab- surveys, however, have been conducted dur- lished. The laminate occlusal topography ing this same period, which encompasses found in Eliurus is reminscent ofmolar struc- about 75 percent of nesomyine specimens ture in the Philippine murid Phloeomys, a with known collecting dates. The bias and much larger rodent believed to be an arboreal insufficiency ofthese data are plainly evident folivore (Eisenberg, 1978). and underscore the conclusion that the re- The range of incisor development within productive phenology of no species popula- the genus also invites investigation. In par- tion of Eliurus is understood. ticular, the weak incisors and short incisive

REFERENCES Allen, G. M. opsis ofMicroryzomys. Bull. Am. Mus. 1939. A checklist of African mammals. Bull. Nat. Hist. 191: 83 pp. Mus. Comp. Zool., Harvard, 83: 763 Carleton, M. D., and D. F. Schmidt PP. 1990. Systematic studies of Madagascar's en- Carleton, M. D. demic rodents (Muroidea: Nesomyi- 1980. Phylogenetic relationships in neotom- nae): an annotated gazetteer of collect- ine-peromyscine rodents (Muroidea) ing localities ofknown forms. Am. Mus. and a reappraisal of the dichotomy Novitates 2987: 36 pp. within New World Cricetinae. Misc. Corbet, G. B., and J. E. Hill Publ. Mus. Zool., Univ. Michigan, 157: 1980. A world list of mammalian species. 146 pp. London: British Museum (Natural His- Carleton, M. D., and G. G. Musser tory), viii + 226 pp. 1984. Muroid rodents. In S. Anderson and J. 1991. A world list of mammalian species, 3rd K. Jones (eds.), Orders and families of ed. London: Natural History Museum Recent mammals ofthe world, pp. 289- Publ., vii + 243 pp. 379. New York: Wiley, 686 pp. Eisenberg, J. F. 1989. Systematic studies of oryzomyine ro- 1967. A comparative study in rodent ethology dents (Muridae, Sigmodontinae): a syn- with emphasis on evolution ofsocial be- 50 AMERICAN MUSEUM NOVITATES NO. 3087

havior, I. Proc. U.S. Natl. Mus. 122 1896b. On the general results of a zoological (3597): 1-51. expedition to Madagascar in 1894-96. 1978. The evolution ofarboreal herbivores in Proc. Zool. Soc. London, pp. 971-981. the Class Mammalia. In G. G. Mont- 1897. On the Malagasy rodent genus Brach- gomery (ed.), The ecology of arboreal yuromys; and on the mutual relations folivores, pp. 135-152. Washington of some groups of the Muridae (Hes- D.C.: Smithsonian Institution Press, 574 peromyinae, Microtinae, Murinae, and PP. "Spalacidae") with each other and with Ellerman, J. A. the Malagasy Nesomyinae. Proc. Zool. 1940. The families and genera of living ro- Soc. London, pp. 695-720. dents. Vol. 1, Rodents other than Mur- Malcolm, J. R. idae. London: British Museum (Natural 1990. Estimation of mammalian densities in History), xxvi + 689 pp. continuous forest north of Manaus. In 1941. The families and genera of living ro- A. H. Gentry (ed.), Four Neotropical dents. Vol.2, Family Muridae. London: forests, pp. 339-357. New Haven and British Museum (Natural History), xii London: Yale Univ. Press, xiii + 627 + 690 pp. PP. 1949. The families and genera of living ro- Milne Edwards, A. dents. Vol. 3, Appendix II [Notes on the 1885. Description d'une nouvelle espece de rodents from Madagascar in the British rongeur provenant de Madagascar. Ann. Museum, and on a collection from the Sci. Nat., Zool. Paleontol. 20: Article 1 island obtained by Mr. C. S. Webb]. bis. London: British Museum (Natural His- Minkoff, E. tory), v + 210 pp. 1965. The effects on classification of slight al- Grandidier, A. terations in numerical technique. Syst. 1885. Histoire physique, naturelle, et poli- Zool., 14: 196-213. tique de Madagascar. Volume 1. His- Musser, G. G. toire de la geographie. Paris, 351 pp. 1979. Results of the Archbold Expeditions, Hershkovitz, P. No. 102. The species of Chiropodomys, 1962. Evolution of Neotropical cricetine ro- arboreal mice ofIndochina and the Ma- dents (Muridae) with special reference lay Archipelago. Bull. Am. Mus. Nat. to the phyllotine group. Fieldiana, Zool. Hist. 162: 377-445. 46: 1-524. 1981. Results of the Archbold Expeditions, Honacki, J. H., K. E. Kinman, and J. W. Koeppl No. 105. Notes on systematics of Indo- 1982. Mammalian species of the world. Kan- Malayan murid rodents, and descrip- sas: Assoc. Syst. Coll., ix + 694 pp. tions of new genera and species from Koechlin, J. Ceylon, Sulawesi, and the Philippines. 1972. Flora and vegetation of Madagascar. In Bull. Am. Mus. Nat. Hist. 168: 225- R. Battistini and G. Richard-Vindard 334. (eds.), Biogeography and ecology in Musser, G. G., and L. R. Heaney Madagascar, 145-190. The Hague: A. 1992. Philippine rodents: definitions of Tar- Junk, xv + 765 pp. somys and Limnomys plus a prelimi- Lavocat, R. nary assessment of phylogenetic pat- 1978. Rodentia and Lagomorpha. In V. J. terns among native Philippine murines Maglio and H. B. S. Cooke (eds.), Evo- (Murinae, Muridae). Bull. Am. Mus. lution of African mammals, pp. 69-89. Nat. Hist. 211: 138 pp. Cambridge: Harvard Univ. Press, ix + Musser, G. G., and C. Newcomb 641 pp. 1983. Malaysian murids and the giant rat of MacPhee, R. D. E. Sumatra. Bull. Am. Mus. Nat. Hist. 174: 1987. The shrew tenrecs of Madagascar: sys- 327-598. tematic revision and Holocene distri- Petter, F. bution ofMicrogale (Tenrecidae, Insec- 1959. Un noveau rongeur de Madagascar (Ne- tivora). Am. Mus. Novitates 2889: 45 somyinae): Macrotarsomys ingens nov. pp- sp. Mammalia 23: 139-148. Major, C. I. Forsyth 1961. Affinites des genres Spalax et Brach- 1896a. Descriptions of four additional new yuromys (Rongeurs, Cricetidae). Mam- mammals from Madagascar. Ann. Mag. malia 25: 485-498. Nat. Hist., ser. 6, 17: 461-463. 1962. Un noveau rongeur Malgache: Brachy- 1994 CARLETON: MADAGASCAR'S RODENTS 51

tarsomys albicauda villosa. Mammalia classification of mammals. Bull. Am. 26: 570-572. Mus. Nat. Hist., 85: 1-350. 1972. The rodents of Madagascar: the seven Stephenson, P. J. genera of Malagasy rodents. In R. Bat- 1987. The ecology and microhabitat segrega- tistini and G. Richard-Vincard (eds.), tion of small mammals within lowland Biogeography and ecology in Madagas- tropical rainforest of north-east Mada- car, pp. 661-666. The Hague: Dr. W. gascar. Independent Project, Univ. Junk B. V. Publishers, xv + 765 pp. London, 62 pp. 1975. Family Cricetidae: Subfamily Neso- Swofford, D. L. myinae. Part 6.2: 4 pp. In J. Meester 1985. PAUP: Phylogenetic analysis using par- and H. W. Setzer (eds.), The mammals simony, Version 2.4.1. Illinois Natural of Africa. An identification manual. History Survey, Champaign, Illinois. Washington: Smithsonian Institution Thomas, 0. Press. 1895. On a new species ofEliurus. Ann. Mag. 1990. Relations de parente des rongeurs de Nat. Hist., ser. 6, 26: 164-165. Madagascar. Atti dei Convegni Lincei 1908. A new species of the Mascarene genus 85: 829-837. Eliurus. Ann. Mag. Nat. Hist., ser. 8, 2: Quay, W. B. 453-454. 1954. The anatomy of the diastemal palate in Voss, R. S. microtine rodents. Misc. Publ. Mus. 1988. Systematics and ecology of ichthy- Zool., Univ. Michigan, 86: 41 pp. omyine rodents (Muroidea): patterns of Rand, A. L. morphological evolution in a small 1932. Mission Franco-Anglo-Americaine a adaptive radiation. Bull. Am. Mus. Nat. Madagascar. Notes de voyage. L'Osieau Hist. 188: 259-493. et Rev. Francaise Ornithol., n. ser., 2: Voss, R. S., and L. F. Marcus 227-282. 1992. Morphological evolution in muroid ro- 1936. The distribution and habits of Mada- dents II. Craniometric factor divergence gascar birds. A summary of the field in seven Neotropical genera, with ex- notes of the Mission Zoologique Fran- perimental results from Zygodontomys. co-Anglo-Americaine a Madagascar. Evolution 46: 1918-1934. Bull. Am. Mus. Nat. Hist. 72: 143-499. Wahlert, J. H. Repenning, C. A. 1985. Cranial foramina of rodents. In W. P. 1968. Mandibular musculature and the origin Luckett and J.-L. Hartenburger (eds.), of the subfamily Arvicolinae (Roden- Evolutionary relationships among ro- tia). Acta Zool. Cracoviensia 13: 29-72. dents, a multidisciplinary analysis, pp. Rode, P. 311-332. New York: Plenum Press, xiii 1945. Catalogue des types de Mammiferes du + 721 pp. Museum National d'Histoire Naturelle. Webb, C. S. IV. Ordre des Rongeurs. Bull. Mus. Natl. 1954. The odyssey of an animal collector. Hist. Nat., ser. 2, 17: 131-182. London: Longmans, xv + 368 pp. Schlitter, D. A. Winge, H 1985. African rodents of special concern: a 1941. The interrelationships of the mamma- preliminary assessment. In W. Z. Lid- lian genera. Volume 2. Rodentia, Car- icker (ed.), Rodents: a world survey of nivora, Primates. Copenhagen: C. A. conservation concern, pp. 33-39. Oc- Reitzels Forlag, 376 pp. (transl. from cas. Pap. IUCN Species Survivial Com- Danish by E. Deichmann and G. M. mission 4: 60 pp. Allen). Simpson, G. G. 1945. The principles of classification and a 52 AMERICAN MUSEUM NOVITATES NO. 3087

APPENDIX 1 17. Fanovana, 500 m (including 8 km from Fa- novana), 18°55'S/48°34'E. Gazetteer of Eliurus 18. 18 km E Perinet [= Andasibe], ca. Collecting Localities 18056'/48031 'E. 19. Perinet [= Andasibe], 915 m (including 1, The specimens of Eliurus reported in the pre- 42 2, and 13 km E), 18°56'S/48°25'E. ceding species accounts represent principal col- 20. 55 km along route to Anosibe, ca. lecting sites, which are listed below together with 19020'S/48014'E. the coordinates used to map distributions. The localities are grouped under current provincial divisions and arranged by consecutive number from Antananarivo Province north to south along the eastern versant of Mad- 21. Mandraka, 1220 m, 18°55'S/47°56'E. agascar and from south to north along the western (see fig. 24). Nearby localities whose coordinates Fianarantsoa Province are virtually the same are indicated in parentheses, 22. Ampitambe [= Ampitabe], 900 m, ca. and current synonyms of older geographic names 20022'S/47046'E. are provided in brackets [=]. Latitude and longi- 23. Ambohimitambo, 1200 m, 20043'S/47023'E. tude figures correspond to that portion of the lo- 24. 12 km E Andraina [= Manandroy] (includ- cality designation printed in boldface. Additional ing 14 km E), 1500 m, ca. 21009'S/47°23'E. locality information and rationale for use of these 25. 3 km by road NNW Vohiparara, 1225 m, geographic coordinates are discussed by Carleton 21013'S/47022'E. and Schmidt (1990). 26. Ambodiamontana, 7 km by road W Rano- mafana, 950 m, 21°16'S/47°26'E. Antsiranana Province 27. 2 km NE Andrambovato, 575 and 625 m, 1. Montagne d'Ambre [= Ambohitra], 1000 m, 21030'S/47027'E. 1 2030'S/4901 O'E. 28. 1 km NW Andrambovato, 875 m, 2. One day W Andapa, 1800 m, ca. 21030'S/47025'E. 1 4039'S/49022'E. 29. 12 km E Ifanadiana, ca. 21°22'S/47°47'E. 3. Antalaha, near sea level, 14053'S/50017'E. 30. 0.5 km N Kianjavato, 300 m, 21023'S/47052'E. Toamasina Province 31. 9 km ESE Kianjavato, 250-500 m, 21024'S/47057'E. 4. Ankovana [= Ankovona], 40 km NE Ma- 32. Fianarantsoa, south of, 21026'S/47005'E. roantsetra, 275 m, 15018'S/49059'E. 33. Vinanitelo, 1300 m, 21043'S/47016'E. 5. 3 km E Andranofotsy, 12 km NE Maroan- 34. Andringitra, 22020'S/46055'E. tsetra, near sea level, ca. 15025'S/49049'. 35. 6 mi E Ivohibe (including 15 mi E), 1525 6. Antalavia, eastern side Antongil Bay, near m, 22030'S/47000'E. sea level, 15°47'S/50001'E. 36. 20 km by road W Vondrozo, 500 m, ca. 7. Hiaraka, near Maroantsetra, 850 m, ca. 22048'S/47010'E. 1 5010'S/49030'E. 37. 20 mi S Farafangana, 4 mi from sea, 8. 20 km SW Maroantsetra, near sea level, 23002'S/47044'E. 15°031 'S/49038'E. 9. 8 mi W Rantabe, Antongil Bay, 150 m, ca. Toliara 1 5042'S/49030'E. Province 10. 10 km WSW Maintimbata, 40 km SW Ma- 38. 5 mi E Bevilany, 245 m, ca. roantsetra, 450-625 m, 15046'S/49036'E. 25000'S/46040'E. 11. 16 mi E Imerimandroso, Lac Alaotra, 1065 39. 35 mi E Tulear [= Toliara], m, 17024'S/48042'E. 23012'S/44012'E. 12. 9 km N Didy, 1000 m, ca. 18002'S/48032'E. 40. Tsilambana, ca. 20050'S/44000'E. 13. Sihanaka Forest, ca. 1 8005'S/48030'E. 41. Morondava, 20017'S/44°17'E. 14. 10 mi NW Lohariandava (including 12 mi 42. Beroboka, 7 km from sea (including Anal- NW), 455 m, 18°42'S/48°35'E. abe), 19058'S/44036'E. 15. Rogez [= Andekaleka], 18048'S/48037'E. 16. 13 mi N Rogez [= Andekaleka], 395 m, 1 8038'S/48037'E. 1994 CARLETON: MADAGASCAR'S RODENTS 53

50 0 200

Kllometers

Fig. 24. Principal collecting localities of specimens of Eliurus reported in this study. Numbered localities correspond to those listed in the gazetteer (Appendix 1). Shaded areas indicate highlands above 1000 m. 54 AMERICAN MUSEUM NOVITATES NO. 3087

APPENDIX 2 APPENDIX 2-(Continued) Descriptive Statistics for Selected Cranial and Ex- ternal Variables and OTUs of Eliurus Species and OTU N Mean Range SD ellermani OTU 19 2 6.3 6.3-6.3 Species and OTU N Mean Range SD Postpalatal Length Occipitonasal Length minor OTU 2 7 10.2 9.6-11.0 0.5 minor OTU 2 9 29.7 28.8-30.9 0.8 minor OTU 4 12 10.7 10.0-11.2 0.4 minor OTU 4 12 30.1 28.7-31.3 0.9 myoxinus OTU 6 5 13.0 12.7-13.4 0.3 myoxinus OTU 6 6 36.1 35.0-36.9 0.7 myoxinus OTU 7 4 14.1 13.0-14.7 0.8 myoxinus OTU 7 4 36.9 34.9-38.1 1.4 majori OTU 8 5 12.7 11.9-13.2 0.6 majori OTU 8 5 36.3 35.2-37.5 0.9 penicillatus OTU 9 14 12.8 11.5-13.8 0.7 penicillatus OTU 9 14 36.0 32.9-37.4 1.4 tanala OTU 10 16 14.4 12.9-15.7 0.9 tanala OTU 10 11 40.8 38.2-44.1 1.9 tanala OTU 11 18 14.4 13.9-15.5 0.3 tanala OTU 11 18 41.1 38.5-43.8 1.5 webbi OTU 15 19 13.7 11.8-14.8 0.8 webbi OTU 15 20 38.8 34.4-41.0 1.6 webbi OTU 17 9 13.9 12.5-14.8 0.6 webbi OTU 17 11 39.0 36.1-41.8 1.5 petteri OTU 18 3 13.5 13.1-13.9 0.4 petteri OTU 18 3 38.3 37.6-38.8 0.6 ellermani OTU 19 1 15.5 - ellermani OTU 19 2 43.2 42.6, 43.8 Length of Bony Palate Length of Rostrum minor OTU 2 9 5.8 5.1-6.3 0.4 minor OTU 2 9 9.9 9.1-10.7 0.5 minor OTU 4 12 6.2 5.4-6.6 0.3 minor OTU 4 13 10.1 9.2-10.8 0.5 myoxinus OTU 6 5 7.7 7.4-7.9 0.2 myoxinus OTU 6 6 12.3 12.0-12.5 0.2 myoxinus OTU 7 6 7.4 7.1-7.9 0.3 myoxinus OTU 7 6 12.1 11.4-12.7 0.5 majori OTU 8 5 7.3 6.9-7.7 0.3 majori OTU 8 5 12.5 12.0-13.1 0.5 penicillatus OTU 9 14 6.7 6.3-7.4 0.3 penicillatus OTU 9 14 12.3 10.8-13.2 0.7 tanala OTU 10 15 9.4 8.2-11.0 0.7 tanala OTU 10 15 14.4 13.3-16.4 0.9 tanala OTU 11 18 9.2 8.2-10.1 0.4 tanala OTU 11 18 14.8 13.3-15.9 0.7 webbi OTU 15 19 8.5 7.3-9.0 0.4 webbi OTU 15 20 13.7 11.8-14.8 0.8 webbi OTU 17 11 8.4 7.7-9.2 0.5 webbi OTU 17 11 13.6 12.4-14.6 0.8 petteri OTU 18 3 8.1 7.6-8.4 0.5 petteri OTU 18 3 13.5 13.0-13.9 0.5 ellermani OTU 19 2 9.9 9.2, 10.7 ellermani OTU 19 2 15.6 15.1, 16.1 Length of Incisive Foramen Greatest Zygomatic Breadth minor OTU 2 9 4.2 4.0-4.4 0.12 minor OTU 2 7 14.4 13.9-15.2 0.4 minor OTU 4 13 3.9 3.5-4.3 0.14 minor OTU 4 13 15.0 14.4-15.7 0.4 myoxinus OTU 6 6 4.6 4.4-4.9 0.20 myoxinus OTU 6 5 17.4 17.0-17.8 0.4 myoxinus OTU 7 6 5.0 4.6-5.4 0.31 myoxinus OTU 7 5 18.2 17.5-19.1 0.7 majori OTU 8 5 5.9 5.5-6.1 0.25 majori OTU 8 5 18.8 18.3-19.3 0.5 penicillatus OTU 9 14 5.4 5.0-5.9 0.31 OTU 9 14 17.9 15.9-19.2 0.9 penicillatus tanalaOTU 10 16 5.4 4.1-6.4 0.57 tanala OTU 10 16 19.5 17.1-21.2 1.3 tanalaOTU 11 18 5.5 4.9-6.1 0.37 tanala OTU 11 18 19.3 18.3-20.6 0.7 webbi OTU 15 20 5.0 4.0-5.5 0.38 webbi OTU 15 20 18.2 15.7-19.2 0.9 webbiOTU 17 11 5.2 4.8-6.2 0.42 webbi OTU 17 9 18.0 16.2-19.0 0.8 petteriOTU 18 3 4.0 3.7-4.1 0.23 petteri OTU 18 3 17.2 16.6-17.9 0.7 ellermaniOTU 19 2 5.6 5.4, 5.8 ellermani OTU 19 2 21.1 20.6, 21.7 Interorbital Breadth Breadth of Bony Palate across Mls minor OTU 2 9 4.9 4.7-5.2 0.2 minor OTU 2 9 5.8 5.6-6.0 0.14 minor OTU 4 13 4.9 4.7-5.2 0.1 minor OTU 4 13 6.0 5.8-6.2 0.14 myoxinus OTU 6 6 5.7 5.5-6.0 0.2 myoxinus OTU 6 6 7.0 6.5-7.3 0.31 myoxinus OTU 7 6 5.4 5.1-5.8 0.2 myoxinusOTU 7 6 6.9 6.6-7.4 0.29 majori OTU 8 5 5.2 5.0-5.5 0.2 majori OTU 8 5 7.7 7.1-8.3 0.50 penicillatus OTU 9 14 5.3 5.1-5.6 0.2 penicillatus OTU 9 14 7.3 6.8-7.9 0.33 tanala OTU 10 16 6.0 5.6-6.4 0.2 tanalaOTU 10 16 8.1 7.6-8.6 0.33 tanala OTU 18 5.9 5.6-6.8 0.3 tanalaOTU 11 18 7.9 7.6-8.6 0.23 webbi OTU 15 20 5.8 5.1-6.2 0.3 webbi OTU 15 20 7.3 6.8-7.8 0.28 webbi OTU 17 11 5.7 5.3-6.0 0.2 webbiOTU 17 11 7.5 7.1-7.7 0.21 petteri OTU 18 3 5.4 5.2-5.6 0.2 petteri OTU 18 3 6.9 6.6-7.1 0.25 1994 CARLETON: MADAGASCAR'S RODENTS 55

APPENDIX 2-(Continued) APPENDIX 2-(Continued) Species and OTU N Mean Range SD Species and OTU N Mean Range SD

ellermani OTU 19 2 8.1 7.9-8.4 - tanala OTU 11 17 156 144-175 9.8 Length of Maxillary Toothrow webbi OTU 15 18 147 135-159 7.6 webbi OTU 17 12 137 0.12 120-149 6.7 minor OTU 2 10 4.1 3.9-4.3 petteri OTU 18 2 133 130, 136 0.08 minor OTU 4 13 4.2 4.0-4.3 ellermani OTU 19 1 152 myoxinus OTU 6 9 5.1 4.8-5.5 0.24 myoxinus OTU 7 9 4.9 4.8-5.0 0.10 Tail Length majori OTU 8 5 6.4 6.1-6.8 0.26 minor OTU 2 10 119 109-126 -5.3 penicillatus OTU 9 14 6.0 5.7-6.3 0.15 minor OTU 4 10 125 110-141 8.8 tanala OTU 10 18 5.8 5.4-6.2 0.20 myoxinus OTU 6 9 141 125-149 7.3 tanalaOTU 11 18 5.7 5.5-6.0 0.14 myoxinus OTU 7 5 142 133-160 10.7 webbi OTU 15 20 5.2 4.7-5.4 0.18 majori OTU 8 2 177 170-183 webbi OTU 17 14 5.3 5.0-5.7 0.20 tanala OTU 10 12 183 166-204 11.8 petteri OTU 18 3 5.0 4.9-5.1 0.10 tanala OTU 11 14 185 163-210 12.5 ellermaniOTU 19 2 5.7 5.6, 5.8 webbi OTU 15 15 179 165-195 8.2 webbi OTU 17 12 175 155-195 10.8 Width of First Upper Molar petteri OTU 18 2 191 178, 205 minorOTU 2 10 1.10 1.06-1.13 0.03 ellermani OTU 19 1 177 minor OTU 4 13 1.14 1.02-1.19 0.05 myoxinusOTU 6 9 1.37 1.25-1.48 0.08 Dry Hind Foot Length myoxinus OTU 7 9 1.31 1.27-1.40 0.04 minor OTU 4 11 22.6 22.0-23.5 0.5 majori OTU 8 5 1.67 1.17-1.78 0.12 myoxinus OTU 6 9 26.3 25.0-28.5 1.1 penicillatus OTU 9 14 1.57 1.49-1.63 0.04 myoxinus OTU 7 7 26.5 25.5-28.0 1.1 tanalaOTU 10 18 1.61 1.43-1.79 0.09 majori OTU 8 4 28.5 27.0-29.5 1.1 tanala OTU 11 18 1.53 1.42-1.68 0.05 penicillatus OTU 9 8 28.7 27.5-30.0 0.9 webbiOTU 15 20 1.38 1.23-1.53 0.07 tanala OTU 10 15 33.3 30.0-36.5 1.8 webbiOTU 17 14 1.42 1.35-1.57 0.06 tanala OTU 11 15 32.9 31.5-34.5 0.9 petteriOTU 18 3 1.40 1.35-1.47 0.06 webbi OTU 15 17 30.6 29.0-32.0 0.8 ellermaniOTU 19 2 1.62 1.61, 1.63 webbi OTU 17 12 30.7 29.5-32.0 0.7 petteri OTU 18 2 32.3 31.5, 33.0 Head-and-Body Length ellermani OTU 19 2 33.5 33.0, 34.0 90-116 7.9 minor OTU 2 10 101 Weight minor OTU 4 11 106 95-116 6.5 myoxinus OTU 6 9 128 114-136 7.5 minor OTU 4 11 34 25-39 4.6 myoxinus OTU 7 7 135 115-145 9.9 tanala OTU 11 17 90 66-115 12.5 majori OTU 8 2 152 145-159 webbi OTU 15 14 78 64-93 10.1 tanala OTU 10 16 154 124-176 16.0 petteri OTU 18 1 74 Recent issues of the Novitates may be purchased from the Museum. Lists of back issues of the Novitates, Bulletin, and Anthropological Papers published during the last five years are available free of charge. Address orders to: American Museum of Natural History Library, Department D, Central Park West at 79th St., New York, New York 10024.

This paper meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper).