Cerradomys langguthi, Percequillo & Hingst-Zaher & Bonvicino, 2008

Percequillo, Alexandre R., Hingst-Zaher, Erika & Bonvicino, Cibele R., 2008, Systematic Review of Genus Cerradomys Weksler, Percequillo and Voss, 2006 (Rodentia: Cricetidae: Sigmodontinae: Oryzomyini), with Description of Two New Species from Eastern Brazil, American Museum Novitates 2008 (3622), pp. 1-48 : 13-18

Cerradomys langguthi , new species

Figures 1 , 3 , 5 , 8 ; tables 1 and 2

HOLOTYPE: MN 69786 , an adult specimen of unknown sex collected by Alfredo Langguth (original field number AL3655), on December 2, 1995. The holotype consists of a skull with an incomplete right zygomatic arch and a partial postcranial skeleton. 1 A bone marrow suspension of cells in Carnoy’s fixative (methanol:acetic acid) and a liver tissue sample preserved in ethanol are housed at Laboratório de Biologia e Parasitologia de Mamíferos Reservatórios Silvestres , Instituto Osvaldo Cruz –FIOCRUZ, under the original field number AL 3655. Cytochrome b DNA data were deposited in GenBank with the accession number AF181276 .

Selected skull dimensions of holotype are: CIL, 32.1; LD, 9.6; LM, 4.95; BM1, 1.45; LIF, 7.15; PB, 5.7; BR, 5.65; LN, 13.55; LPB, 5.2; HB, 10.4; LIB, 5.35; CZL, 24.3; OL, 11.8.

PARATYPES: All specimens listed under ‘‘Specimens Examined’’ are herein assigned as paratypes of Cerradomys langguthi .

TYPE LOCALITY: The holotype of Cerradomys langguthi was collected at Corredor São João–Fazenda Pacatuba , Sape´ , State of Paraíba, Brazil, at ca. 07 ° 029S, 35 ° 099 W. Fazenda São João and Fazenda Pacatuba are Atlantic Forest remnants, which are connected by a corridor of native vegetation .

DISTRIBUTION: The known collection localities of C. langguthi are distributed on the left bank of Rio São Francisco , throughout the Brazilian states of Pernambuco, Paraíba, Ceará, and Maranhão. In Pernambuco, Paraíba, and Ceará, distributional records extend from coastal lowlands to inland highlands and mountain ranges. Collection records in Maranhão are associated with lowlands of the central portion of the state (fig. 1) .

1 Although the specimen MN 69786 is lacking its skin, it was selected as the holotype, because it is the only available specimen with skull, karyotype, and tissue sample, together the most informative traits for recognition of this species .

32.1 mm).

TABLE 1 Diagnostic Traits and Morphologic Comparisons of the Six Known Species of Cerradomys Abbreviatons : w, wool hairs; c, cover hairs; g, guard hairs.

TABLE 2 Descriptive Statistics of External and Skull Measurements for the Three Species of Cerradomys from Eastern Brazil Mean ± standard deviation, (minimum-maximum), N.

ETYMOLOGY: This species is named after Dr. Alfredo Ricardo Langguth Bonino for his long-term dedication and commitment to the development of Brazilian mammalogy.

DIAGNOSIS: Cerradomys langguthi is characterized by small body size, short and dense dorsal pelage, dorsal body color orange grizzled with brown, head color grayish, ventral body color grayish or slightly yellowish, short and narrow sphenopalatine vacuities, restricted to presphenoid, exposing partially orbitosphenoid, alisphenoid strut absent, deep palatal fossae (complex posterolateral palatal pits), and a unique chromosomal formula (2n 5 48–50, FN 5 56).

MORPHOLOGICAL DESCRIPTION: Head and body size small (table 2); tail length longer than head and body (102%–144% of head and body length); hindfeet moderately narrow and long (21%–24% of head and body length), with large and fleshy interdigital, thenar, and hypothenar pads; pinnae rounded and small (11.3%–17% of head and body length). Dorsal pelage short and dense (table 1), consisting of short, dense underfur (wool hairs; thin, wavy, short) and longer and lax overfur (cover and guard hairs; thick, long). Dorsal body color buffy orange densely grizzled with black; wool hairs (range: 5–8 mm) with basal part grayish and distal part (1/10 of total length) orange or brown; cover hairs long (range: 9–12 mm), with distal 1/4 dark brown with a subterminal orange band; guard hairs sparse and long (range: 13–16 mm), with distal half entirely black or dark brown. Anterior half of head (until eyes) covered with gray-based and white- or buffy-tipped hairs, clearly distinct from color of posterior half of head and dorsal body fur. Ventral pelage composed of wool underfur and cover and guard hairs, with individual hairs grayish-based and tipped with white, buffy or yellowish; general ventral color grayish, buffy, or yellowish, slightly grizzled, and distinctively lighter than dorsal pelage. Flanks bright orange; banded cover hairs and dark guard hairs rare. Mystacial vibrissae long, reaching but not surpassing pinnae when laid back. Tail slightly bicolored to bicolored, covered with short, sparse brown hairs and scales on dorsal surface and unpigmented hairs and scales on ventral surface. Dorsal surface of hind foot white, covered with short, entirely white hairs (only young individuals present hairs with 3/4 distal portion white and basal 1/4 grayish or washed brown); ungual tufts sparse, shorter than claws especially on digit I; ventral surface naked, unpigmented, with four interdigital pads and two tarsal pads (thenar and hypothenar). Pinnae covered internally with short orange hairs and externally with orange, brown-tipped hairs.

Skull size small (tables 1, 2; figs. 3, 5, 8). Rostrum long and broad, tapering, with inflated capsular projection of nasolacrimal foramen, and flanked by deeply excavated zygomatic notches; interobital region long and narrow (table 2), converging anteriorly, with dorsolateral margins with sharp and welldeveloped supraorbital crests; braincase oblong, with prominent temporal crests. Zygomatic plate (in lateral view) projected forward, with dorsal free margin rounded and anterior margin straight or slightly concave, and zygomatic spine absent. Incisive foramina long (averaging about 74.4% of length of diastema), with lateral margins concave and diverging posteriorly, and wider posteriorly; posterior margins extending or not between the alveolus of upper first molars. Palate long and wide (sensu Hershkovitz, 1962); posterolateral palatal pits numerous and complex, recessed in very deep palatal fossae; palatal excrescences rarely present. Mesopterygoid fossa narrow, with anterior margin rounded or slightly acute, not reaching the alveolus of M3; bony roof of mesopterygoid fossa perforated by short, narrow to wide sphenopalatine vacuities, restricted to presphenoid, partially or totally exposing the orbitosphenoid. Alisphenoid strut absent (buccinator-masticatory foramen and ovale foramen confluent). Postglenoid foramen large and nearly semicircular in shape separated from small or absent subsquamosal fenestra (small in 62.5% and absent in 37.5% of 16 specimens examined for this trait), by a wide hamular process of squamosal. Tegmen tympani weakly overlapping squamosal; posterior suspensory process of squamosal absent. Ectotympanic bullae globose; eustachian tube short, with distinct medial laminae in a few specimens; stapedial process short and wide, overlapping squamosal; bony process dorsal to stapedial process present, overlapping squamosal.

Mandible long and deep (figs. 5, 8); coronoid process large, falciform or triangular, nearly equal to condyloid process; superior notch shallow; angular process short, not surpassing the condyloid process posteriorly; inferior notch shallow; capsular process of lower incisor well developed.

Incisors, upper and lower molars as for the genus (no mesoloph/mesolophid reduction was observed in C. langguthi ). Mammary counts and soft anatomy (stomach and glans penis) as described for the genus.

KARYOLOGY: The Cerradomys langguthi holotype shows a karyotype with 2n 5 50 and FN 5 56 (table 7). The autosomal complement of specimens with 2n 5 50 comprises four biarmed pairs (1 large, 3 medium to small pairs) and 20 acrocentric pairs (3 large and 17 medium to small pairs). The X chromosome is a medium-sized acrocentric and the Y chromosome a small-sized acrocentric. Variation in diploid number is due to centric fusion affecting two acrocentric pairs.

Maia and Hulak (1981) reported a variation on the chromosomal diploid number in Pernambuco samples (Tupanatinga, Buíque, Bom Conselho, Capoeiras, Correntes, Panelas, Caruaru, São Lourenço, and Exu), with 2n 5 48, 49, and 50; all karyotypes present the same fundamental number FN 5 56. The karyotype of the holotype is coincident with the 2n 5 50, FN 5 56 karyotype presented by Maia and Hulak (1981). Moreover, when examining specimens from Buique, one of the localities sampled by Maia and Hulak (1981), we found them to be conspecific with C. langguthi .

The 2n 5 48-49-50 polymorphism reported by Maia and Hulak (1981) results from multiple centric fusions. The karyotype observed in the Exu sample, 2n 5 46, FN 5 56, differs from the basic complement by the presence of two large submetacentric pairs formed by centric fusions. Bonvicino (2003) recognizes this karyotype as a distinct karyomorph, altough we do not have compelling morphologic or molecular evidence to consid- er it a separate form.

NATURAL HISTORY: Cerradomys langguthi inhabits several vegetation types: the coastal lowland humid Atlantic Forest (locally called ‘‘Zona da Mata’’); the open and relatively dry forests (locally called as ‘‘Agreste’’) in the zone between the more humid and dense coastal forest and the more open and drier Caatinga;

the arbustive and arboreal Caatinga; and the forests restricted to humid slopes of mountain ranges in areas of Caatinga (‘‘Brejos’’).

Paiva (1973) associated this species with sugar-cane plantations, near humid and mesic areas, in Ceará. This habitat is also pointed by Mares et al. (1981) and Streilein (1982) as typical for C. langguthi in Pernambuco. Karimi et al. (1976) also obtained this species in natural and cultivated fields, reporting nests in more humid grass patches. We trapped specimens of C. langguthi at secondary forests and shade coffee plantations on the slopes of Serra de Baturité (a typical ‘‘Brejo’’) in Ceará.

SPECIMENS EXAMINED: BRAZIL: CEARÁ: Pacoti (Sítio Friburgo), Serra de Baturite´: M: MZUSP ARP 11 , 45 , 77 . Crato (Guaribas, Sítio Páscoa) : UFMG YL 264 , 289 . MARANHÃO: Alto Parnahyba (5 Alto Parnaíba): F : FMNH 26446 . Fazenda Lagoa Nova , Bacabal: F : MPEG 23482 . PARAÍBA: Corredor São João-Fazenda Pacatuba, Sape´: I : MN 69786 (holotype of C. langguthi ). João Pessoa: M : UFPB 31 , 92 , 386 ; F: UFPB 2081 ; I: UFPB 2079 . Mamanguape , Fazenda Alagamar, Mamanguape: M : UFPB 2061 . Areias, Mata de Pau Ferro , Areias: M : UFPB 2065 . Natuba : M : UFPB 24 , 38 , 41 , 63 , 175 , 258 , 2066 , 2073 , 2078 ; F: UFPB 25 , 31 , 35 , 257 , 2068 . Pirauá , Natuba: M : UFPB 1 , 178 , 180 , 181 , 182 , 183 , 221 , 2059 ; F: UFPB 12 , 220 ; I: UFPB 47 . Salgado São Félix : M : UFPB: M 28 , 37 , 39 , 45 , 46 , 228 , 231 , 2057 ; F: UFPB 29 , 37 , 233 ; I: UFPB 229 . Teixeira, Pico do Jabre : M : UFPB 1955 , 1977 , 2367 ; F: UFPB 1976 , 2060 , 2366 . PERNAMBUCO: Exu: M : MZUSP 18900–1 , 18906 , 18908 , 18910 ; F: MZUSP 18904 , 18909 ; I: MZUSP 18903 . Fazenda Saco , Exu: M : MZUSP 18905 . Macaparana : UFPB 14 , 33 , 224 , 269 , 271 , 272 , 2056 , 2070 ; F: UFPB 15 , 21 ; I: UFPB 148 . São Vicente Ferrer : M : UFPB 19 , 150 , 151 , 267 , 2072 ; F: UFPB 18 , 38 , 155 , 156 . Sítio Mata Verde , Buíque: M : MZUSP 20604 . PIAUí: Arara: M : FMNH 25246 ; F: FMNH 25247 .

Figures

Fig. 1. Known collection localities of the six species of Cerradomys in South America. The area delimited by a square is detailed in figure 2. See gazetteer (appendix 1), where numbers are associated with collection localitites. Brazilian states acronyms: AL, Alagoas; BA, Bahia; CE, Ceará; DF, Distrito Federal; Go, Goiás; MA, Maranhão; MT, Mato Grosso; MS, Mato Grosso do Sul; MG, Minas Gerais; PB, Paraíba; PE, Pernambuco; PI, Piauí; SP, São Paulo; SE, Sergipe; TO, Tocantins.

Fig. 3. Dorsal and ventral cranial views of three species of Cerradomys. Left: C. langguthi from Corredor São João—Fazenda Pacatuba, Paraíba (MN 69786; CIL, 32.1 mm). Middle: C. vivoi from Fazenda Canoas, Juramento, Minas Gerais (MN 61663; CIL, 32.92 mm). Right: C. subflavus from Parque Nacional da Serra do Cipó, Minas Gerais (MN 31393; CIL, 32.41 mm).

Fig. 5. Lateral cranial and mandible views of three species of Cerradomys. Top: C. langguthi from Corredor São João—Fazenda Pacatuba, Paraíba (MN 69786; CIL, 32.1 mm). Middle: C. vivoi from Fazenda Canoas, Juramento, Minas Gerais (MN 61663; CIL, 32.92 mm). Bottom: C. subflavus from Parque Nacional da Serra do Cipó, Minas Gerais (MN 31393; CIL, 32.41 mm).

Fig. 8. Dorsal, ventral, and lateral cranial views of holotype of Cerradomys langguthi (MN 69786; CIL,