A NEW SPECIES OF GRACILE MOUSE OPOSSUM, GENUS GRACILINANUS (DIDELPHIMORPHIA: DIDELPHIDAE), FROM ARGENTINA

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1 Journal of Mammalogy, 8():82 8, 2002 A NEW SPECIES OF GRACILE MOUSE OPOSSUM, GENUS GRACILINANUS (DIDELPHIMORPHIA: DIDELPHIDAE), FROM ARGENTINA M. MÓNICA DíAZ,* DAVID A. FLORES, AND RUBÉN M. BARQUEZ Sam Noble Oklahoma Museum of Natural History, 201 Chautauqua Avenue, University of Oklahoma, Norman, OK (MMD) Programa de Investigaciones de Biodiversidad Argentina and Colección Mamíferos Lillo, Universidad Nacional de Tucumán, Miguel Lillo 205, 000 Tucumán, Argentina (MMD, DAF, RMB) Consejo Nacional de Investigaciones Científicas y Técnicas, 000 Tucumán, Argentina (RMB) A new species in the genus Gracilinanus is described on the basis of a specimen found in a museum collection. The new species is known only from the type locality, which is located in the Yungas phytogeographic province near the Parque Nacional Calilegua, Jujuy Province, Argentina. Presently, the area is highly disturbed because of agricultural activity, mainly the cultivation of sugar cane. External, dental, and cranial morphology are described, and morphometric data as well as comparisons with other species in the genus Gracilinanus are presented. Key words: Argentina, gracile mouse opossum, Gracilinanus, systematics, taxonomy Gardner and Creighton (1989) proposed the name Gracilinanus for the species included in the microtarsus group of Tate (19). This genus is widely distributed across the forests and woodlands of the Neotropics (Hershkovitz 1992). Hershkovitz (1992) included 9 species in the genus, but Gardner (199) recognized only 6 species, excluding kalinowskii, longicaudus, and perijae. Recently, kalinowskii was included in the new genus Hyladelphys by Voss et al. (2001). Previously, only 2 species were known from Argentina, Gracilinanus agilis and G. microtarsus (Chébez 1996; Contreras 1982, 198; Heinonen Fortabat and Chébez 1997; Massoia 1980; Massoia and Fornes 1972; Olrog and Lucero 1981; Redford and Eisenberg 1992). During the examination of mammals from Jujuy Province, Argentina, at the American Museum of Natural History (AMNH), New York, one of us (MMD) * Correspondent: pidbatuc@infovia.com.ar found a specimen of the genus Gracilinanus that was not assignable to any of the known species. This specimen was collected by F. Contino in 1962 when the province of Jujuy was less disturbed by agricultural development. During the last decades, the province was highly disturbed, principally because of cultivation of sugar cane and deforestation; this may be the reason for not finding new records of this species in the area, in spite of intensive collecting efforts. In this study we describe a new species of Gracilinanus, a genus that has been included recently in the fauna of northwestern Argentina (G. agilis) by Flores et al. (2000). Description of the new species was based on cranial, dental and external morphology, morphometric data, and comparisons with other species of Gracilinanus and 1 species of Hyladelphys. MATERIALS AND METHODS External, cranial, and dental measurements were recorded for the new species, for speci- 82 Downloaded from

2 August 2002 DÍAZ ET AL. NEW SPECIES OF GRACILINANUS 825 mens of 7 other species of Gracilinanus, and for the recently described Hyladelphys kalinowskii (Table 1; Appendix I). Cranial measurements were taken with digital calipers to the nearest 0.05 mm. Measurements and abbreviations are as follows: total length (ToL), from tip of snout to tip of tail; tail length (TL), between point of insertion of tail into the body and last caudal vertebra; hind foot length (HFL), from heel to tip of the longest digit, including the claw; ear length (EL), between notch and tip of the pinna; mass (M), body weight in grams; condyloincisive length (CIL), from anteriormost incisor to posteriormost projection of occipital condyle; occipitonasal length (ONL), from anteriormost edge of nasal to posteriormost projection of occipital condyle; breadth of braincase (BB), width of cranium measured just posterior to zygomatic arches; postorbital constriction (PC), least distance across cranium measured posterior to postorbital processes; zygomatic breadth (ZB), greatest distance across outer margins of zygomatic arches; mastoidal breadth (MB), width of cranium, including mastoid; length of rostrum (LR), from anterior border of orbit to the anterior border of nasal; length of the nasal (LN), from posterior border to anterior border of nasal; length of maxillary toothrow (LMxT), from anterior margin of alveolus of canine to posterior margin of alveolus of last molar; palatal length (PL), from posterior margin of alveolus of incisor to medial posterior border of palate; width across canines (C C), distance between outer margin of upper canines; width across molars (M M), distance between outer margin of upper last molars. The Numerical Taxonomic and Multivariate Analysis System (Rohlf 199) was used to generate a principal components analysis to evaluate morphological variation among 9 taxa in the genus Gracilinanus and H. kalinowskii. Data for 5 cranial measurements (ONL, BB, PC, ZB, and LN) were taken from specimens examined in this study (Table 1) and from Hershkovitz (1992). These measurements were selected so that all species in the genus could be included in the analysis. The type specimen was compared with museum specimens of several species, including holotypes of G. emiliae, G. longicaudus, G. marica, G. dryas, G. agilis chacoensis, and G. agilis peruana, with holotype of H. kalinowskii, and with descriptions given by Hershkovitz (1992), Gardner and Creighton (1989), Tate (19), and Voss et al. (2001). Color descriptions follow those used by Ridgway (1912). Terminology for description of the skull follows Hershkovitz (1992). Teeth nomenclature follows Reig et al. (1987), and dental terminology follows Tribe (1990). RESULTS Gracilinanus ignitus, new species Holotype. Adult male, skin and skull, AMNH , collected 28 March 1962 by F. Contino. Type locality. Yuto, Departamento Ledesma, Jujuy Province, Argentina (2 8 S, 6 28 W). Distribution. Known only from type locality. Etymology. ignitus (Latin) fiery glowing, referring to strong clay color of the venter. Common names: red-bellied gracile mouse opossum (Spanish: comadrejita de vientre rojo). Diagnosis. Gracilinanus ignitus is a species in the genus Gracilinanus on the basis of the following characters: postorbital processes absent; edges of interorbital region beaded; lambdoidal crests slightly developed; palate well fenestrated; labial and lingual cingula always present on rd premolar. This is 1 of the largest species in the genus and can be distinguished from the other species by the following combination of characters: venter strongly clay colored with a white longitudinal patch on chest; tail weakly bicolored and sparsely haired; periocular ring complete and thin; ratio of tail length to head body length 1.09; pinna about 16% head body length; hind foot about 1% head body length. Cranium differs from that of all other species of Gracilinanus in having the following combination of characters: ascending postorbital process of zygomatic arches well developed (height.51 mm); braincase little inflated; presence of pronounced edges that extend from postorbital area across the temporal Downloaded from

3 826 JOURNAL OF MAMMALOGY Vol. 8, No. TABLE 1. Measurements (in mm, except for mass, which is in g) of species of Gracilinanus. (See text for abbreviations.) ToL TL HFL EL M CIL ONL BB PC ZB MB LR LN LMxT PL C C M M Gracilinanus ignitus holotype Gracilinanus aceramarcae UMMZ Gracilinanus agilis Mean Minimum Maximum n Gracilinanus dryas Mean Minimum Maximum n Gracilinanus emiliae holotype Gracilinanus longicaudus holotype Gracilinanus marica Mean Minimum Maximum n Gracilinanus microtarsus MACN Downloaded from

4 August 2002 DÍAZ ET AL. NEW SPECIES OF GRACILINANUS 827 crests to the lambdoidal crests; lambdoidal crests developed; 2 small posteromedial vacuities present; upper canines well developed (length 2.92 mm); P2 equal or slightly smaller than P. Description. Size large, total length 220 mm; length of head body 105 mm; length of tail 115 mm; length of hind foot 15 mm; length of ear 17 mm. General external characters as for the genus. Tail long (109.5% head body length), slightly haired, with scales visible; scales rounded, arranged in annular rows; spiny hairs per scale, middle scale slightly more than 2 scales long and slightly thicker than other 2 hairs; proximal 11 mm of base of tail well furred with tip practically naked; distal portion (about 20 mm) naked ventrally; pinna large and almost naked; gular gland not evident; claws slightly extended beyond tips of the digits; fore- and hind feet covered with clay colored hairs; soles of fore- and hind feet naked; claws of hind feet covered with a small white tuft; apparently all palmar and plantar tubercles present and separated by a double row of granules (specimen preserved as a skin). Dorsal coloration Snuff Brown overall, with light wash of Clay color and Sayal Brown; dorsal hairs with 2 bands of color, Mouse Gray proximally and Snuff Brown distally. Venter strongly Clay colored extending to sides, cheeks, throat, chin, and feet; hairs of venter unicolored. Chest with a conspicuous narrow and long white patch. Periocular rings black and not well developed. Ears Clay color. Tail slightly bicolored (darker above), Saccardo s Umber above and Tawny Olive below. Feet Clay color. General cranial and dental characters as for the genus. Skull (Fig. 1) large; nasal long, pointed and expanded abruptly at frontomaxillary suture; interorbital region with parallel edges, with crests that extend from postorbital area across temporal crests to lambdoidal crests; constriction behind interorbital region marked; postorbital processes absent; lambdoidal crest developed; FIG. 1. Dorsal (top left) and ventral (top right) views of skull, and lateral (bottom) view of skull and mandible of Gracilinanus ignitus n. sp. Scale: 10 mm. braincase little inflated; zygomatic arches broad, strong, weakly expanded and almost parallel; ascending postorbital process of zygomatic arch well developed but not pointed; palate projecting posteriorly to level of anterior border of postorbital process of jugal; palate well fenestrated, with pairs of vacuities, 1 pair well-developed vacuities of maxillopalatine or mesolateral, 2 pairs small posteromedial or palatine vacuities, and 1 pair posterolateral vacuities; maxillary vacuities absent; posterolateral vacuities about one-third the breadth of last upper molar in length; anteromedial process of alisphenoid portion of bulla was apparently present but lost during preparation of the specimen; tympanic process of the petrosal evident; coronoid process of mandible broad; superior notch straight. Type specimen has adult dentition, I1 longer than other upper incisors; I2 I similar in size, and I5 slightly larger; upper canine well developed and splayed outward; Downloaded from

5 828 JOURNAL OF MAMMALOGY Vol. 8, No. P1 smaller than P2 and P; P2 equal to or slightly smaller than P; main cusps of M1 slightly worn, cusps B and D more developed than other cusps, right side more worn than left; M2 with paracone and protocone more worn than metacone, cusp C slightly evident; M more worn than M2, cusp C not evident; M flattened anteroposteriorly. Lower incisors subequal in size; lower canine notably shorter than upper canine; p1 smaller than p2 and p; protoconid and metaconid well evident, hypoconid lower than entoconid; m2 and m similar to m1, only protoconid more developed; m metaconid the most developed cusp, talonid well worn. Measurements. Table 1. Comparisons. This species was compared with H. kalinowskii, considered by Hershkovitz (1992) as a species of the genus Gracilinanus. H. kalinowskii is distinguished by small size, dorsum and sides cinnamon brown, area between eyes pale, periocular rings broad and extending to base of the ears, venter almost white, braincase inflated, zygomatic arches widely expanded, edges of interorbital region widely divergent posteriorly, palatal vacuities reduced, anteromedial process of aliesphenoid portion of the bulla absent. Differs from all other species of Gracilinanus in coloration. G. microtarsus has the following characteristics that distinguish it from G. ignitus: coloration between tawny and russet; a larger periocular ring; rostrum paler than the rest of body; hairs posterior to throat with gray bases; feet whitish; tail unicolored; claws on hind feet not extending beyond terminal digital pads; rostrum narrow; zygomatic arches widely expanded; lambdoidal crest weakly developed or absent; P2 larger than P. Gracilinanus perijae is similar in size to G. ignitus but can be distinguished by the following characters: venter pale buff, plumbeous bases visible; periocular ring prominent; median interscutular hair brownish and laterals grayish; temporal crest faint; 1 pair of large posteromedial vacuities. Gracilinanus agilis, which is distributed in the same area (Flores et al. 2000), is distinguished by venter buffy-white; periocular ring wider; tail hairier, scales less visible; median interscutular hair different in color than lateral hairs; postorbital processes present or absent; zygomatic arches moderately developed; ascending postorbital process more pointed; 1 pair of large posteromedial vacuities; maxillary vacuities present; canines less developed (height mm); P2 larger than P. Gracilinanus aceramarcae differs from G. ignitus by the following characters: pelage very long and lax; dorsal coloration Mars brown or russet; snout grayish; chin buffy brown; bases of the hairs gray; gular gland evident, skin naked; rostrum narrow; distance between canines small; braincase globose; interorbital region divergent, posterior constriction absent; lambdoidal and temporal crests absent; zygomatic arches thinner and ascending postorbital process pointed; 1 pair of large posteromedial vacuities; bulla larger; crest of basioccipital marked; coronoid process of mandible slender and terminated in sharp curve; superior notch concave. Gracilinanus dryas is distinguished from G. ignitus by pelage long, soft and lax; hairs of venter with gray bases; tail unicolor; rostrum narrow and pointed; interorbital region smooth; edges of interorbital region diverging posteriorly and without ridges; braincase globose; anteromedial process of alisphenoid portion of bulla absent; maxillary vacuities present; 1 pair of large posteromedial vacuities; canines short. Compared with G. ignitus, G. emiliae is smaller; venter buffy white; tail unicolor, very long, about twice the head body length; rostrum short and narrow; interorbital region divergent; braincase globose; maxillary vacuities present; 1 pair of large posteromedial vacuities; canines short. Gracilinanus longicaudus has the following characteristics that distinguish it from Downloaded from

6 August 2002 DÍAZ ET AL. NEW SPECIES OF GRACILINANUS 829 TABLE 2. Principal components analysis among species of Gracilinanus and Hyladelphys. Loading of the characters analyzed along the first components. (See text for abbreviations.) I II III ONL BB PC ZB LN G. ignitus: dorsum cinnamon brown; periocular ring incomplete; venter pale yellow; claw of fore- and hind feet extending to or nearly to tips of digits; tail unicolored; braincase not inflated; interorbital region moderately divergent; 1 pair of large posteromedial vacuities; maxillary vacuities present; P2 slightly larger than P. Gracilinanus marica is distinguished by venter yellowish buffy or cream; throat and sides of neck cream buffy; bases of hairs gray, except those of chin, neck, throat, and a small, narrow band on chest; interorbital ridges not well developed, processes nearly obsolete; zygomatic arches widely expanded; 1 pair of large posteromedial vacuities; maxillary vacuities present; canines small; P2 slightly smaller than P. Phenetic analysis. A principal components analysis of correlations among characters (Table 1; Hershkovitz 1992) was used to evaluate variation in size and shape between G. ignitus and other species in the genus, and with H. kalinowskii. The eigenvalues of the first principal components were.66 (7.16%), 0.7 (1.91%), and 0.8 (9.6%), respectively, explaining 97.69% of total variance. Loadings of the 5 characters analyzed along each of the first components are shown in Table 2. In the bivariate plot of components I and II (Fig. 2a), H. kalinowskii and G. ignitus are clearly separated from the other species along component II, H. kalinowskii is located in the upper part of the plot, whereas G. ignitus is situated in the lower part of the plot. Along component I, G. emiliae, G. FIG. 2. Multivariate relationships of species of Gracilinanus and Hyladelphys. Projections of scores for principal components a) I and II, b) II and III, and c) I and III; extracted from correlations of 5 cranial measurements. Abbreviations of species: A, G. aceramarcae; CH, G. agilis chacoensis; D,G. dryas; E,G. emiliae; I,G. ignitus; K, H. kalinowskii; L, G. longicaudus; MA, G. marica; M, G. microtarsus; P, G. perijae. Downloaded from

7 80 JOURNAL OF MAMMALOGY Vol. 8, No. longicaudus, and H. kalinowskii are located on the left side of the plot, whereas the other species are located to the right. In the bivariate plot of components I and III (Fig. 2c), G. ignitus is located in the lower part of the plot on component III, near G. perijae and G. agilis chacoensis. In the bivariate plot of components II and III (Fig. 2b), G. ignitus is located in the lower left-hand corner of the plot, clearly separated from the other species. Habitat. Type locality of G. ignitus is in the Yungas phytogeographic province and is located near the Parque Nacional Calilegua. Presently, the habitat is highly disturbed. Extensive areas for cultivation of sugar cane and fruits have been established in the region during the last several decades. The habitat of the region is an ecotone between transitional and montane forest, where Anadenantera macrocarpa, Tipuana tipu, and several laurels are the dominant vegetation (Fig. ). Natural history. Nothing is known about the natural history of this species. Other species of didelphid marsupials that were captured in the area include Didelphis albiventris, Lutreolina crassicaudata, Micoureus constantiae, and Thylamys sponsoria. Although the holotype is the only known specimen, the combination of characters of size and coloration allow its taxonomic separation from other species in the genus. FIG.. Habitat of Gracilinanus ignitus, at Arroyo Yuto, Departamento Ledesma, Jujuy Province, Argentina, near type locality. Photo by M. M. Díaz. DISCUSSION Over the last several years, investigations and surveys of mammals in the province of Jujuy have illustrated how poorly the fauna of the province was known. Recently, Díaz and Barquez (1999), Barquez and Díaz (2001), and Flores et al. (2000) reported 10 additional species for Jujuy, thus indicating that the province has a greater mammalian diversity than previously thought. On the other hand, investigators are just now beginning to understand the biology of marsupials of Argentina, with scarce knowledge of systematics and distribution of these species. In general, studies of marsupials have included few specimens or have not included specimens from Argentina (Graipel et al. 1996; Hershkovitz 1997; Marshall 1978; Palma 199, 1995; Palma and Yates 1998); thus, many authors have made errors about specific identity or distributional limits (or both) of species in Argentina. The description of G. ignitus, as well as descriptions of other species within the genus Gracilinanus recently described by Hershkovitz (1992), are based on specimens that were deposited in museum collections decades ago. This certainly reflects the lack of systematic studies, at least in this group, of specimens from South America deposited in museum collections. The genus Gracilinanus has a great diversity and wide distribution in South America, as shown by this study and by Hershkovitz (1992). Systematic studies are needed for this and other groups of mammals of Argentina and the southern cone of South America. The new taxa of mammals from Argentina that have been described (Braun and Mares 1995; Díaz et al. 1999; Mares and Braun 1996; Mares et al. 2000; Williams and Mares 1978) or are being described reflect the lack of systematic studies and biotic surveys in the country. Over the last several decades, the Yungas phytogeo- Downloaded from

8 August 2002 DÍAZ ET AL. NEW SPECIES OF GRACILINANUS 81 graphic province of Argentina has experienced the ever-increasing human impact of agricultural and technological development, cattle ranching, and indiscriminate deforestation. Probably, G. ignitus was affected by the changes in its habitat. Even as it is being described as a new species, it is difficult to know if it still exists in the region. RESUMEN Una nueva especie del género Gracilinanus es descripta basándose en un espécimen de museo. La nueva especie es sólo conocida para la localidad tipo, ubicada en la Provincia Fitogeográfica de las Yungas, cerca del Parque Nacional Calilegua, provincia de Jujuy, Argentina. Actualmente el área de captura está altamente modificada debido al incremento de cultivos, principalmente de caña de azúcar, que se han establecido en la zona desde muchos años atrás. Se ofrecen descripciones de morfología externa, dental, craneal, y morfometría del nuevo taxón, y se compara con todas las especies del género Gracilinanus actualmente reconocidas. ACKNOWLEDGMENTS Fieldwork was supported by grants from CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas of Argentina) and CIUNT (Consejo de Investigaciones de la Universidad Nacional de Tucumán, Argentina) which we thank for the support given to R. M. Barquez. We extend special thanks to R. Voss of the American Museum of Natural History, New York, P. D. Jenkins of the British Museum (Natural History), London, M. A. Mares of the Sam Noble Oklahoma Museum of Natural History, Norman, Oklahoma, P. Myers of University of Michigan Museum of Zoology, Ann Arbor, and William Stanley of Field Museum of Natural History, Chicago, for arranging access to specimens. We thank N. Giannini for his help with the multivariate analysis. We also thank CONI- CET, FOSDIC (Fundación Obras y Servicios para el personal Directivo de la Industria y la Construcción), and the American Museum of Natural History for fellowships provided to M. M. Díaz. LITERATURE CITED BARQUEZ, R. M., AND M. M. DíAZ Bats of the Argentine Yungas: a systematic and distributional analysis. Acta Zoologica Mexicana 82:1 81. BRAUN, J.K.,AND M. A. MARES A new genus and species of phyllotine rodent (Rodentia: Muridae: Sigmodontinae: Phyllotini). Journal of Mammalogy 76: CHÉBEZ, J. C Fauna misionera. Catálogo sistemático y zoogeográfico de los vertebrados de Misiones (Argentina). Editorial Literature of Latin America, Buenos Aires, Argentina. CONTRERAS, J. R Mamíferos de Corrientes I. Nota preliminar sobre la distribución de algunas especies. Historia Natural 2: CONTRERAS, J. R Notas sobre el género Marmosa en el noreste argentino (Marsupialia: Didelphidae). Historia Natural : DíAZ, M.M.,AND R. M. BARQUEZ Contributions to the knowledge of the mammals of the Jujuy Province, Argentina. Southwestern Naturalist :2. DíAZ, M. M., R. M. BARQUEZ, J.K.BRAUN, AND M. A. MARES A new species of Akodon (Muridae: Sigmodontinae) from northwestern Argentina. Journal of Mammalogy 80: FLORES, D. A., M. M. DíAZ, AND R. M. BARQUEZ Mouse opossums (Didelphimorphia, Didelphidae) of northwestern Argentina: systematics and distribution. Zeitschrift für Säugetierkunde 65:1 19. GARDNER, A. L Order Didelphimorphia. Pp in Mammal species of the world: a taxonomic and geographic reference. 2nd ed. (D. E. Wilson and D. M. Reeder, eds.). Smithsonian Institution Press, Washington, D.C. GARDNER, A.L.,AND G. K. CREIGHTON A new generic name for Tate s microtarsus group of South American mouse opossums (Marsupialia: Didelphidae). Proceedings of the Biological Society of Washington 102: 7. GRAIPEL, M., P. R. M. MILLER, AND A. XIMENEZ Contribução e distribuição das subspécies de Lutreolina crassicaudata (Desmarest) (Marsupialia, Mammalia). Revista Brasiliera de Zoologia 1: HEINONEN FORTABAT, S., AND J. C. CHÉBEZ Los mamíferos de los parques nacionales de la Argentina. Monografía Especial, Literature of Latin America 1:1 76. HERSHKOVITZ, P The South American gracile mouse opossums, genus Gracilinanus Gardner and Creighton 1989 (Marmosidae, Marsupialia): a taxonomic review with notes on general morphology and relationships. Fieldiana: Zoology 70:1 56. HERSHKOVITZ, P Composition of the Family Didelphidae Gray, 1821 (Didelphoidea: Marsupialia), with a review of the morphology and behavior of the included four-eyed pouched opossums of the genus Philander Tiedemann, Fieldiana: Zoology 86:1 10. MARES, M. A., AND J. K. BRAUN A new species of phyllotine rodent, genus Andalgalomys (Muridae: Sigmodontinae), from Argentina. Journal of Mammalogy 77: Downloaded from

9 82 JOURNAL OF MAMMALOGY Vol. 8, No. MARES, M. A., J. K. BRAUN, R.M.BARQUEZ, AND M. M. DíAZ Two new genera and species of halophytic desert mammals from isolated salt flats in Argentina. Occasional Papers, Museum of Texas Tech University 20:1 27. MARSHALL, L. G Lutreolina crassicaudata. Mammalian Species 91:1. MASSOIA, E Mammalia de Argentina. I. Los mamíferos silvestres de la provincia de Misiones. Iguazú 1:15. MASSOIA, E., AND A. FORNES Presencia y rasgos etoecológicos de Marmosa agilis chacoensis Tate en las provincias de Buenos Aires, Entre Ríos y Misiones (Mammalia-Marsupialia-Didelphidae). Revista de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (Buenos Aires), serie 1, Biología y Producción Animal 9: OLROG, C. C., AND M. M. LUCERO Guía de los mamíferos Argentinos. Fundación Miguel Lillo, Tucumán, Argentina. PALMA, R. E Historical relationships of South American opossums of the genus Thylamys (Marsupialia: Didelphidae): evidence from molecular systematics and historical biogeography. Ph.D. dissertation, University of New Mexico, Albuquerque. PALMA, R. E Range expansion of two South American mouse opossums (Thylamys, Didelphidae) and their biological implications. Revista Chilena de Historia Natural 68: PALMA, R. E., AND T. L. YATES Phylogeny of southern South American mouse opossums (Thylamys, Didelphidae) based on allozyme and chromosomal data. Zeitschrift für Säugetierkunde 6:1 15. REDFORD, K. H., AND J. F. EISENBERG Mammals of the Neotropics. The southern cone: Chile, Argentina, Uruguay, Paraguay. University of Chicago Press, Chicago, Illinois 2:1 0. REIG, O. A., J. A. W. KIRSCH, AND L. J. MARSHALL Systematic relationships of the living and Neocenozoic American opossum-like marsupials (suborder Didelphimorphia), with comments on the classification of these and the Cretaceous and Paleogene New World and European metatherians. Pp in Possums and opossums: studies in evolution, I (M. Archer, ed.). Surrey Beatty and Sons, Sydney, New South Wales, Australia. RIDGWAY, R Color standards and color nomenclature. R. Ridgway and A. Hoen and Company, Washington, D.C. ROHLF, F. J NTSYS-pc. Numerical taxonomy and multivariate analysis system. Version Exeter Software, New York. TATE, G. H. H. 19. A systematic revision of the marsupial Genus Marmosa. Bulletin of the American Museum of Natural History 66: TRIBE, C. J Dental age classes in Marmosa incana and other didelphoids. Journal of Mammalogy 71: VOSS, R. S., D. P. LUNDE, AND N. B. SIMMONS The mammals of Paracou, French Guiana: a Neotropical lowland rainforest fauna. Part 2. Nonvolant species. Bulletin of the American Museum of Natural History 26:1 26. WILLIAMS, D.F.,AND M. A. MARES A new genus and species of phyllotine rodent (Mammalia: Muridae) from northwestern Argentina. Annals of Carnegie Museum 7: Submitted 5 June Accepted 28 January Associate Editor was Brett R. Riddle. APPENDIX I Specimens examined. All specimens examined are listed with localities and catalog numbers. Acronyms of collections are as follows: AMNH, American Museum of Natural History, New York; BMNH, British Museum (Natural History), London, United Kingdom; CEM, Colección Elio Massoia y familia, Buenos Aires, Argentina; CML, Colección Mamíferos Lillo, Tucumán, Argentina; FMNH, Field Museum of Natural History, Chicago, Illinois; IADIZA-CM, Instituto Argentino de Investigaciones en Zonas Áridas, Mendoza, Argentina; MACN, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Buenos Aires, Argentina; MLP, Colección de Mamíferos, Museo de La Plata; La Plata, Argentina; OMNH, Sam Noble Oklahoma Museum of Natural History, Norman, Oklahoma; UMMZ, University of Michigan Museum of Zoology, Ann Arbor. Gracilinanus ignitus (1). See species description. Gracilinanus aceramarcae (1). BOLIVIA. La Paz Department: Río Aceramarca, 1 km S Yerbani, 1 (UMMZ ). Gracilinanus agilis agilis (12). BRAZIL. Federal District, 25 km S of Brasilia, IBGE, 1 (OMNH 1769); Federal District, 20 km S of Brasilia, (OMNH 1765, 1766, 1767); Federal District, 25 km S of Brasilia, (OMNH 1770, 1771, 19077, 19078); Federal District, Fazenda, Agua Limpia, 1 (OMNH 1768); Mato Grosso, 108 km S of Poconé, 1 (OMNH 1772); Mato Grosso, 115 km S of Poconé, IBDF, Base de Pesquisas, 1 (OMNH 177); Mato Grosso, 115 km S of Poconé, IBDF, Base Pesquisas, 1 (OMNH 177). Gracilinanus agilis buenavistae (1). BOLIV- IA. Santa Cruz Department: Buenavista, 1 (MACN 50177). Gracilinanus agilis chacoensis (). AR- GENTINA. Buenos Aires Province: Arroyo Ñacurutú, Zarate, 2 (MACN 9.5, MLP 2.X.50.2); Arroyo Ñacurutú-Isla Robles, Zarate, 2 (MLP 2.X.50., MLP 2.X.50.5); Arroyo Ñacurutú-Isla Talavera, Zarate, 1 (MLP Downloaded from

10 August 2002 DÍAZ ET AL. NEW SPECIES OF GRACILINANUS 8 2.X.50.1); Isla Talavera, Zarate 1 (MLP 5.VIII.98.9); Campana, Delta, Canal 6, 1 (CML 1810); Ensenada Reserva Natural Punta Lara, 2 (MLP 9.IX.97., MLP.IX.97.). Entre Ríos Province: Villa Elisa-Arroyo Perucho Verna, Colon, 1 (MLP 0.VI.98.1). Jujuy Province: Ingenio La Esperanza, 1 (CEM 691); Santa Bárbara, 1 (AMNH ). Salta Province: Ingenio San Martín del Tabacal, lote Milagros, 1 (CML 5911, 5912, 591, 591, 5915, 5916, 5917, 5918, 5919, 5920, 5922, 592, 5925, 5926); Ingenio Tabacal, 2 (IADIZA-CM 6201, 620). Misiones Province: Puerto San Juan, Candelaria, 1 (MLP 17.VII.96.); Río Uruguaí, a 0-km de Puerto Bemberg, 1 (MACN 925); San Ignacio Desembocadura Arroyo Yabebiry, 1 (MLP 0.X.95.16, MLP.VIII.98.12). PARA- GUAY. Sapucay, (BMNH.2..9,..7.22,..7.2, holotype). Gracilinanus agilis peruana (1). PERU. Tingo Maria, 2,000 ft [610 m], Huamaco, 1 (BMNH holotype). Gracilinanus dryas (). VENEZUELA. Merida: Montes de las Sierras, 1 (BMNH ); Alechicer,,000 m, 1 (BMNH ); Montanas Alechicera,,000 m, 1 (BMNH ); Selvas Culatas,,000 m, 1 (BMNH holotype). Gracilinanus emiliae (1). BRAZIL. Para, 1 (BMNH holotype). Gracilinanus longicaudus (10). COLOM- BIA. Meta: San Juan de Arama, Los Micos, 1,00 ft [96 m], 1 (FMNH 8792 holotype). Gracilinanus marica (). VENEZUELA. 2 (BMNH , ). Merida: Rio Albarengas, 1 (BMNH holotype). Gracilinanus microtarsus (1). BRAZIL. Uruguayana, 1 (MACN 197). Hyladelphys kalinowskii (1). PERU. Cuzco: Quispicanchi, Hacienda Cadena, 1,000 m, 1 (FMNH holotype). Downloaded from