Podogymnura minima Sanborn, 1953

Balete, Danilo S., Heaney, Lawrence R., Rickart, Eric A., Quidlat, Roselyn S., Rowsey, Dakota M. & Olson, Link E., 2023, A re-assessment of diversity among Philippine gymnures (Mammalia: Erinaceidae Podogymnura), with a new species from eastern Mindanao, Zootaxa 5228 (3), pp. 244-266 : 256-257

Podogymnura minima Sanborn, 1953

Podogymnura truei minima Sanborn 1953 . Mammals from Mindanao, Philippine Islands collected by the Danish Philippine Expedition, 1951-1952. Videnskabelige Meddelelser Dansk Naturhistorisk Forening 115:283–288.

Podogymnura truei: Heaney & Morgan 1982 . Tab. 1-2 (part, DMNH 5949-5953).— Poduschka & Poduschka 1985. Tab. 1 C-D, 2B, Abb. 6, 16 (part, FMNH 92777, 92780-81, SMF 31430, 31443, 31755, AMNH 164482; ZMC 1311).— Heaney et al. 2006. Tables 2 – 6, Fig. 8 (part, FMNH 74852, 92777, 92778, 92779, 92780, 92781,146592, 146594, 146962, 146963, 146964; 147782, 147783, 147790, 147800, 147801, 147802, 147803, 147804, 147808, 147809, 147810, 147811, 147812, 147813, 147814, 147815, 148003, 148004, 148005, 148006, 148010, 148011, 148012, 148013, 148016, 148017, 148018, 148019, 148050, 148053, 148077, 148078, 148083, 148084, 148085, 148087, 166456, 166457, 166458, 167375, 167376, 167377, 167378).

Holotype. Zoologisk Museum, Copenhagen, catalog number 1311. Adult female collected on 16 December 1951, field number F. Salomonsen K-4. Skin and skull.

Type locality. Mt. Kitanglad , Bukidnon Province, Mindanao Island, Philippines, 1600 m ( Fig. 1 ) .

Measurements. Tables 1 and 2.

Specimens examined. Mindanao Island, Bukidnon Province, Kitanglad Range, Mt. Kitanglad , 10.7 km S, 2.9 km W of Sumilao Poblacion, 1,450 m elev., 8°11’10”N, 124°55’10”E (FMNH 166456, 166457, 167375 – 167378); Mt. Kitanglad , 11.5 km S, 2.2 km W of Sumilao Poblacion, 1,500 m elev., 8°11’0”N, 124°55’35”E (FMNH 166458); Mt. Kitanglad , 1,600 m elev. (FMNH 74852); Mt. Imbayao , 15 km S, 7 km E of Baungon, San Vicente Municipality, 1,800 m elev., 8°9’N, 124°45’E (FMNH 146592, 146594, 146962 – 146964); Mt. Nangkabulos , 16.5 km S, 4 km E of Camp Phillips, 1,900 m elev., 8°10.5’N, 124°51’E (FMNH 147782, 147783, 147808, 147809, 147810, 147790, 148077, 148078); Mt. Nangkabulos , 15.5 km S, 4 km E of Camp Phillips, 2,250 m elev., 8°9.5’N, 124°51’E (FMNH 147800 – 147804, 147811, 147812, 147813, 147814, 147815, 148083, 148084, 148085, 148087); Mt. Dulangdulang, 15 km S, 11 km W of Dalwangan, Malaybalay City , 2,375 m elev., 8°7.5’N, 124°56’E (FMNH 148003, 148004, 148005, 148006, 148018, 148050); Mt. Dulang-dulang , 15 km S, 11.5 km W of Dalwangan, Malaybalay City , 2,600 m elev., 8°7.5’N, 124°56’E (FMNH 148010, 148011, 148012, 148013); Mt. Dulang-dulang , 15 km S, 12.5 km W of Dalwangan, Malaybalay City , 2,800 m elev., 8°7.5’N, 124°56’E (FMNH 148016, 148017, 148018, 148019, 148053); Mt. Kitanglad , Malaybalay City, 5,000 ft. elev. (ca. 1,524m), (FMNH 92777, 92778, 92779); Mt. Kitanglad , Malaybalay City 6,000 ft. elev. (ca. 1,829 m), FMNH 92780, 92781 ).

Distribution. Documented from Mt. Kitanglad Range, north-central Mindanao Island, including Mts. Dulangdulang, Imbayao, and Nangkabulos ( Fig. 1 ).

Emended diagnosis. Overall, the smallest species of the genus (HB = 137 – 152 mm); tail short (49 – 66 mm), about 36% of head and body, pale grayish-brown dorsally and unpigmented ventrally; hindfoot short (HF = 33 – 37 mm, 23% of HB; Table 1) and uniformly pale brown. Dorsal pelage dark reddish-brown, long and soft with conspicuous golden-brown tips; underfur dark gray, dense and wavy, shorter than guard hairs; guard hairs black, with most long, straight, and tapered, but some distally flattened and slightly bent. Ears and feet pale, lightly pigmented. Skull ( Fig. 5 , Table 2) slender and tapered (CIL = 37.28 – 39.78 mm), sagittal and nuchal crests poorly developed and inconspicuous, rostrum long (LR = 15.00 – 17.57 mm), cranium narrow (BBC = 15.40 – 16.22 mm). Incisive foramina relatively narrow and short. Anterior surface of basioccipital nearly smooth, lacking or barely showing a short ridge running medially parallel to the bullae; paired concavities absent. Tips of tympanic wings of basioccipital short and nearly straight (rather than longer and curved medially). Upper toothrow short (I1 – M3 = 18.71 – 21.06 mm), P3 without lingual lobe; mandible relatively slender (LMI = 28.63 – 30.65 mm), as are its angular, coronoid and condyloid processes. P4 relatively small and triangular. Cusp at base of talonid on m1 and m2 absent.

Comparisons. Podogymnura minima and P. aureospinula : P. minima is the smallest and P. aureospinula the largest member of the genus ( Tables 1 and 2), and they are easily distinguished on that basis. The long, soft pelage of P. minima strongly contrasts with the short and stiff, bristly fur of P. aureospinula ; in the former species, goldenbrown highlights visible only at the tips of black guard hairs, but the latter has conspicuous golden-yellow guard hairs. Paired concavities in basioccipital between bullae that are present in P. aureospinula and P. intermedia are absent. The lingual lobe of P3 is present in P. aureospinula but absent in P. minima . P4 relatively small and triangular, vs. large and squarish. Cusp at base of talonid on m 1 and m 2 absent, vs. present.

Podogymnura minima and P. intermedia n. sp: pelage of P. minima is soft, similar to that of P. intermedia from Mt. Kampalili, and different from the rough and bristly dorsal pelage of P. intermedia from Mt Hamiguitan. P. intermedia has conspicuous dorsal golden-yellow streaks or speckling, whereas P. minima has smaller, less apparent golden-brown speckles. P. minima is smaller than P. intermedia n. sp. in nearly all respects, especially the large specimens from Mt. Hamiguitan ( Tables 1 and 2, Figs. 6A and 6B ). It is notable that P. intermedia from Mt. Hamiguitan has an especially long and broad rostrum, long post-palatal region, and thick mandible relative to P. minima ( Table 2). Further comparisons in the new species description below.

Podogymnura minima and P. truei: See comments above; external differences include small overall size in P. minima (mean HB = 145 mm vs. 148 mm, TV = 54 vs. 56 mm). The skull of P. minima is slightly but consistently shorter and more gracile overall, with a narrower rostrum, less inflated braincase, and lower sagittal crest; P. truei has slightly shorter condylar process of the mandible ( Tables 2, 3, Figs. 5 , 6A, 6B ).

Karyology. Specimens from the Kitanglad Range have a standard karyotype of 2N = 40, FN = 76 ( Rickart 2003).

Ecology. P. minima has been recorded in montane and mossy forest, from 1300 m to 2800 m elevation; it was among the most abundant small mammals in middle to high-elevation montane and mossy forest on Mt. Kitanglad ( Heaney et al. 2006). They are nocturnal, feeding on the surface of the ground. Diet based on stomach contents is composed largely of earthworms, with some arthropods, including hymenopterans and coleopterans. Pregnancy was recorded from March to June; litter size (n = 9) was one, rarely two. Other species of native small mammals documented in the elevational range of P. minima were Crocidura beatus , Tupaia everetti , Apomys hylocoetes , A. insignis , Batomys salomonseni , Crunomys suncoides , Limnomys bryophilus , L. sibuanus , Rattus everetti , and Tarsomys apoensis ( Heaney et al., 2006) .

Figures

FIGURE 1. Map of Mindanao and adjacent islands showing some major topographic features; mountains where Podogymnura truei (Mt.Apo), P. minima (Mt. Kitanglad Range), P. aureospinula (Bucas Grande and Dinagat Islands), and P. intermedia n. sp. (Mt. Hamiguitan and Mt. Kampalili) occur, and other important peaks, are shown.

FIGURE 5. Photographs of skulls of Podogymnura intermedia (holotype, FMNH 186805, A-D), P. truei (FMNH 56169, E-H), and P. minima (FMNH 146594; I-L). All skulls approximately life size.

FIGURE 6. A. Bivariate plot of condylo-incisive length (CIL) and breadth of braincase (BBC) measurements comparing Podogymnura truei, P. minima, and P. intermedia n. sp. B. Results from the Principal Component Analysis of four small species of Podogymnura (excluding P. aureospinula) based on 15 cranial, dental, and mandibular measurements (see text).

FIGURE 8. Dorsal (A), ventral (B) and lateral (C) views of the skull and lateral view of the mandible (D) of Podogymnura intermedia (FMNH 186805, holotype); scale bar refers to these images. E, occlusal view of the second mandibular molar of Podogymnura intermedia holotype; arrow points to a small cusp at the base of talonid, between the entoconid and metaconid.