Marmosa (Micoureus) constantiae Thomas, 1904

Voss, Robert S., Fleck, David W. & Jansa, Sharon A., 2019, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 3: Marsupials (Didelphimorphia), Bulletin of the American Museum of Natural History 2019 (432), pp. 1-89 : 27-30

Marmosa (Micoureus) constantiae Thomas, 1904

Figure 11A

VOUCHER MATERIAL (TOTAL = 21): Nuevo San Juan (AMNH 268219, 268220, 272667, 272832, 273052, 273079, 273113, 273118; MUSM 11060, 11062, 11064, 13294–13296, 15317, 15310–15313), Jenaro Herrera (MUSM 23806), Santa Cecilia (FMNH 87117).

OTHER INTERFLUVIAL RECORDS: None that can be confidently associated with this species (see below).

IDENTIFICATION: Two species of the subgenus Micoureus (“woolly mouse opossums,” formerly recognized as a distinct genus; Gardner and Creighton, 2008) are sympatric at Nuevo San Juan, and the same two species occur sympatrically at several other localities south of the Amazon in eastern Peru and western Brazil. Specimens of both species collected sympatrically in western Brazil were identified as Micoureus demerarae (Thomas, 1905) and Mic. regina (Thomas, 1898) by Patton et al. (2000), who, however, cautioned that different names might apply to their material. Among other possibilities, they ( Patton et al., 2000: 72) suggested that “ constantiae might best be considered a junior synonym of demerarae ,” but the former name has priority. Therefore, Marmosa constantiae is the binomen used in this report for the demerarae - like woolly mouse opossum of southwestern Amazonia. 6 For reasons explained in the next account, we use the name Mar. rutteri Thomas, 1924 , for the woolly mouse opossum that Patton et al. (2000) called Mic. regina .

Marmosa constantiae and M. rutteri are large mouse opossums with broadly overlapping external and craniodental measurements (table 7). Where they occur sympatrically in eastern Peru and western Brazil, both have drab, somewhat woolly dorsal fur; long, all-dark tails with rhomboidal scales arranged in spiral series; almost completely ossified palates (lacking palatine fenestrae, and with short-narrow maxillopalatine openings); well-developed postorbital processes (in most mature adults); and small auditory bullae. As in other members of the subgenus Micou-

6 Based on our unpublished sequence results (which are too extensive to effectively summarize in this report), the material we refer to this species forms a distinct haplogroup within a large and complex clade that also includes voucher material referable to the nominal taxa demerarae ; domina Thomas, 1920; limae Thomas, 1920; and phaea Thomas, 1899. The species we provisionally recognize as Marmosa constantiae occurs south of the Amazon from the base of the Andes to the left bank of the Tapajós.

TABLE 7

reus, gular glands are absent in both sexes, and large adult males have well-developed medial and lateral carpal tubercles ( Voss et al., 2014). Although there are several pelage and craniodental differences that allow confident identification of specimens in hand (table 8), M. constantiae and M. rutteri are otherwise so alike that unvouchered records (e.g., of “ Micoureus cinereus ” at Jenaro Herrera; Fleck and Harder, 1995) cannot be confidently associated with one or the other species.

As described and illustrated by Patton et al. (2000: 65–77), the ventral pelage is mostly graybased in Marmosa constantiae , but it is mostly self-yellowish in M. rutteri . In the former species, self-yellowish fur is restricted to the throat, groin, and (sometimes) to a narrow streak along the midline of the chest and abdomen; the fur on

TABLE 8

the insides of the fore- and hind limbs is always gray-based. In M. rutteri , by contrast, self-yellowish fur extends over the chin, throat, chest, and groin, and along the insides of the fore- and hind limbs; a median abdominal band of selfyellowish fur is always present, and it is at least as broad as or broader than the flanking lateral zones of gray-based fur.

Another taxonomically informative external trait is the length of the dorsal fur, which appears to be consistently longer in Marmosa constantiae than in sympatric M. rutteri . In our material from the Yavarí-Ucayali interfluve, the middorsal fur of adult M. constantiae is about 12–15 mm long, whereas the dorsal fur of M. rutteri from our region and adjacent lowlands is only about 8–11 mm. Although these observed ranges almost overlap, the modal fur lengths for these species (about 13 mm and 9 mm, respectively) correspond to visibly and tactilely distinct phenotypes.

A third diagnostically useful external trait (illustrated by Patton et al., 2000: fig. 53) concerns the tail, which has a more conspicuously furry base in Marmosa constantiae than in M. rutteri . Not only does the caudal fur (identical in color and texture to the fur of the rump) extend distally further along the tail in constantiae , but the hairs that comprise the caudal fur are longer in this species than in rutteri . Measured from skins in our material of constantiae , this fluffyfurred tail base extends distally for about 28 mm (on average) with hairs that are about 10 mm long, whereas the homologous average values for rutteri are about 16 mm and 5 mm.

Although Patton et al. (2000: table 13) found statistically significant differences for most craniodental measurements in same-sex comparisons of Marmosa constantiae (“ Micoureus demerarae ”) and M. rutteri (“ Micoureus regina ”), these species have broadly overlapping morphometric distributions, such that no measurement (nor any ratio of measurements that we computed) is diagnostic. Unmagnified comparisons of cranial morphology are likewise uninformative, but two dental features (visible under low magnification) are useful for species recognition. In constantiae the postprotocrista (the posteriormost of the two enamel crests that pass labially from the apex of the protocone; Voss and Jansa, 2009: fig. 20) is short, because it terminates at or near the base of the metacone, whereas the postprotocrista is much longer in rutteri , extending labially well beyond the base of the metacone on the posterior surface of the tooth. On the lower molars, a posterior cingulid (a small enamel shelf at the posterolabial base of the hypoconid) is consistently absent in constantiae , whereas a small but persistent posterior cingulid is usually present, at least on m2, in rutteri .

Unlike the Peruvian material described above, the holotype of Marmosa constantiae (BMNH 3.7.7.157, from Chapada dos Guimarães, Mato Grosso, Brazil; Thomas, 1904a), other specimens from Mato Grosso, and many specimens from eastern Bolivia (Beni and Santa Cruz departments, see below) have tails that are one-third to one-half whitish distally. Nevertheless, all the material that we refer to M. constantiae is morphologically similar in other respects, and sequenced specimens from Mato Grosso and eastern Peru belong to the same well-defined mtDNA haplogroup (the “SW-S” clade of Patton and Costa, 2003: fig. 9). Therefore, we interpret geographic differences in caudal markings as intraspecific variation.

Unfortunately, the epithet constantiae has often been misapplied (e.g., by Tate, 1933; Flores et al., 2007; Gardner and Creighton, 2008; Gutiérrez et al., 2010; de la Sancha et al., 2012; Voss et al., 2014) to another widespread species of woolly mouse opossum, for which the oldest available name is Marmosa rapposa Thomas, 1899 . As recognized in this report, M. rapposa (with type locality at Huadquiña, near Cusco, Peru; Ceballos- Bendezu, 1981) ranges at middle elevations in Andean cloud forests from Junín department, Peru, throughout the Bolivian Yungas to northeastern Argentina (budini Thomas, 1920, from Jujuy is a junior synonym); at lower elevations, this species occurs in Cerrado woodlands from eastern Bolivia across central Brazil to eastern Paraguay. Although specimens of M. rapposa resemble the holotype of M. constantiae in having white-tipped tails and yellowish underparts, they differ in other respects (table 8), most notably in having well-developed palatine fenestrae (fig. 11B), long postprotocristae, well-developed posterior cingulids on m1–m3, and highly divergent mtDNA sequences (Voss et al., in prep.).

ETHNOBIOLOGY: The Matses do not distinguish this species from other pouchless, longtailed, black-masked species of small opossums (all known as chekampi; see the account for Marmosa , above) and therefore have no particular beliefs about it.

MATSES NATURAL HISTORY: The Matses have no definite knowledge of this species.

REMARKS: Of the 19 specimens of Marmosa constantiae collected at Nuevo San Juan, 11 were trapped or shot in primary upland forest; 2 were trapped in primary floodplain forest; 4 were trapped, shot, or caught by hand in secondary growth (abandoned swiddens); and 2 were caught by hand in Matses houses. Of 10 specimens accompanied by information about capture height, 2 were trapped on the ground, 1 was trapped on a fallen log, and 7 were trapped or shot in trees or on lianas at estimated heights ranging from 0.4 to 4 m above the ground. Our single specimen from Jenaro Herrera was trapped at a height of 17 m in a tree at the edge of a clearing.

OTHER SPECIMENS EXAMINED (TOTAL = 62): Bolivia — Beni, Río Iténez frente Costa Marques (AMNH 209158–209162), Río Mamoré lado este frente Cascajal (AMNH 210397); Pando, La Cruz (MSB 57001). Brazil — Amazonas, Altamira on right bank of Rio Juruá (MVZ 190309– 190312), Coleção Vira-Volta on left bank of Rio Juruá (MVZ 190316–190318), Penedo on right bank of Rio Juruá (MVZ 190301–190303), Seringal Condor on right bank of Rio Juruá (MVZ 190305–190307), Ilhazinha on left bank of Rio Juruá (MVZ 190313, 190314); Mato Grosso, Chapada dos Guimarães (AMNH 384, BMNH 3.7.7.157 [holotype], OMNH 37209), Fazenda Noirumbá (MVZ 197415), Reserva Ecológica Cristalino (MVZ 197407–197414). Peru — Cuzco, 15.9 km SW Pilcopata (FMNH 174443), 2 km SW Tangoshiari (MUSM 13412, 13414, 13415), Pagoreni (MUSM 14139, 14141); Madre de Dios, Altamira (FMNH 98029), 13.5 km NW Atalaya (MUSM 19830), Hacienda Amazonía (FMNH 138852), Itahuanía (FMNH 84254, 84255), Reserva Cuzco Amazónico (KU 144092, 144094, 144096–144099, 144103); Pasco, Pozuzo (BMNH 12.1.15.18); San Martín, Área de Conservación Municipal Mishquiyacu Rumiyacu-Almendra (FMNH 203510), Moyobamba (FMNH 19348), Yurac Yacu (BMNH 27.1.1.174–27.1.1.176); Ucayali, Balta (MVZ 136374–136377).

Figures

FIG. 11. Ventral views of palates of A, Marmosa constantiae (AMNH 209162) and B, M. rapposa (MSB 140347). Both specimens are from Bolivia, where these species are externally similar (with mostly selfyellow ventral fur and half-white tails; see text). Both species have maxillopalatine fenestrae (mpf), but only M. rapposa consistently has well-developed palatine fenestrae (pf).