Cryptotis evaristoi, Zeballos & Pino & Medina & Pari & Chávez & Tinoco & Ceballos, 2018

Zeballos, Horacio, Pino, Kateryn, Medina, César E., Pari, Alexander, Chávez, Daniel, Tinoco, Nicolás & Ceballos, Gerardo, 2018, A new species of small-eared shrew of the genus Cryptotis (Mammalia, Eulipotyphla, Soricidae) from the northernmost Peruvian Andes, Zootaxa 4377 (1), pp. 51-73 : 61-67

Cryptotis evaristoi , new species

Zeballos, Pino, Medina, Pari and Ceballos

Holotype. MUSA 7427 , adult male, collected on 20 October 2009 by K. Pino (KPB-191, Figs 8 , 9 ). The specimen includes skin, skull, mandibles, tissues, and partial skeleton in good condition.

Measurements of holotype. Total length 120 mm; head and body length 88 mm; tail length 32 mm; hind foot length 15.6 mm; body mass 12 g; condylobasal length 22.6 mm; breadth of braincase 10.9 mm; breadth of zygomatic plate 2.3 mm; postorbital breadth 5.6 mm; breadth across first unicuspids 2.8 mm; breadth across third unicuspids 3.3 mm; breadth across second molars 5.7 mm; length of palate 10 mm; length of maxillary toothrow 8.4 mm; length of unicuspids tooth row 2.5 mm; length of molariform tooth row 6.0 mm; posterior width of upper first molar 2.0 mm; length of mandible 7.7 mm; height of coronoid process 4.7 mm; height of condylar valley 3.3 mm; height of articular process 4.7 mm; breadth of articular condyle 3.3 mm; articular process to lower third molar 4.7 mm; length of mandibular tooth row 6.8 mm; and length of lower first molar 1.9 mm. Proportions: IO/CBL 0.25; PL/CBL 0.44; ZP/CBL 0.10; ZP/PL 0.23; UTR/CBL 0.11; M2B/PL 0.57; HCP/ML 0.61; AC3/ML 0.60; and AC3/HCP 1.27.

Type locality. Miraflores , San Ignacio, Cajamarca, Peru (5° 12´S and 79° 12´W) at 2,800 m above sea level ( Fig. 1 ).

Paratypes. Several additional specimens were collected by Kateryn Pino, near the ponds in Arrebiatadas, District of Tabaconas, Province of San Ignacio, and Cajamarca Department, northern Peru (5.2 ° S and 79.3 ° W) at 3,200 m above sea level: three adults males ( MUSA 7412 [ KPB 50 ] ; MUSA 7418 [ KPB 87 ] ; MUSA 7419 [ KPB 126 ]), collected on September 26, October 0 1 and 0 6 of 2009 ; an adult female ( MUSA 7428 [ KPB 201 ]), collected at the type locality, on 22 October of 2009 . The adult's males paratypes ( MUSA 7412 [ KPB 50]; MUSA 7418 [ KPB 87]; MUSA 7419 [ KPB 126]) are preserved as dried skins, skulls, and partial skeletons in good conditions. The adult female paratype ( MUSA 7428 [ KPB 201]) is preserved in alcohol.

Diagnosis. Cryptotis evaristoi is a member of the C. thomasi group (for characters defining this group, see Choate 1970; Woodman et al. 2003; and below in description). C. evaristoi is distinguished from all other species of the genus by the following combination of characters: large body size; grayish color on dorsal side; tail short; large forepaws and elongated foreclaws; the face elongated; inflated cranium in dorsal view ( Fig. 8 ) is more rounded to hexagonal; fronto-occipital suture is rounded to triangular in shape; nasal narrow and opening wider; anterior border of nasal does not have a spine-shaped process; pterygoid fossa is wider and shorter; larger zygomatic plate, postorbital breadth, palatal length, the width of M1, mandibular length, and length of the articular process of M3, and M1; secondary cusp of upper incisors are very reduced and about one-third the size of the anterior cusp; interorbital parallel in the dorsal view and not convergent; fourth unicuspid is not in line with other unicuspids; posterior border of the lower incisor reaches the anterior border of PM4; optic foramen partially visible in a lateral view of the skull; and U4 is small and usually visible in the labial view.

Description. Cryptotis evaristoi is a large-sized (HBL = 70–96 mm, W = 11–16 g, CBL = 21.9–22.8 mm) member of the genus Cryptotis. HBL averaging 85.5 mm; body mass averaging 14 g; condylobasal length averaging 22.34 mm; short tail with an average length of 33.7 mm, or about 39.92% of the head and body length. Pelage is dense with a darker back and a paler belly, dorsal side is deep olive to metallic bronze color ( Fig. 9 ), ventral side is a drab citrine color, and hairs are bicolored with a gray base and clearer tips. Ear pinnae are reduced and covered with fur, and the helix, antihelix, and antitragus are poorly developed. Short mystacial vibrissae extend to the anterior edge of the ear. Ventral part of the toes has well-developed granular scales arranged in two longitudinal rows. Claws are long (2.5 mm) and curved, and the thenar pad is developed in the rear position in relation to the hypothenar pad. Skull is moderately inflated and hexagonal in the dorsal view, and the frontooccipital suture is rounded to triangular. Interorbital area is comparatively wide (24.78% of the CBL) and in the dorsal view, it is parallel while the anterior border of the nasal lacks a spine-shaped process. Optic foramina are partially visible in a lateral view. Rostrum is comparatively long (45% of CBL) and the zygomatic plate is moderately wide (10.04% of the CBL). Secondary cusp of the upper incisors is much reduced to about one-third the size of the anterior cusp. Molar hypocone shows a lower development. Entoconids are usually absent and the mesopterygoid fossae are short. U4 are reduced to one-third to one-fourth the size of the unicuspids and are not visible in the labial view and are not in line with other unicuspids. M3 complex. Premolars with protocone are developed but do not have a paraconule. Posterior border of the lower incisor reaches the anterior border of P4. There are two dorsal foramina along the suture between the right and left frontal, and the right is partially obliterated. Mandible has a short posterior region and the sigmoid notches are shallow. Coronoid process is large, high, and leaning back. An upper maxillary row has moderately long unicuspid teeth (11.06% of the CBL). Crests of the protocone and hypocone of the upper first and second molar are pigmented. Third upper molar complex with the postcentrocrista is developed and the mesostyle, metacone, and hypocone are present. Entoconids of m1 and m2 have rounded cusps.

Etymology. The specific name is dedicated to Evaristo Lopez-Tejeda because of his dedication and support for the development of Museo de Historia Natural de la Universidad Nacional de San Agustín (MUSA) of Arequipa, Peru; and for his pledge and devotion to educating and guiding several generations of Peruvian zoologist.

Distribution. The species is found in the montane forest and páramo in the Tabaconas Namballe National Sanctuary at an altitude of 2,700 to 3,780 m above sea level ( Fig. 1 ).

Variation. There was no sexual dimorphism observed with the exception of body mass (Student’s t-test, p = 0.04, 4 females and 13 males), with males heavier than females. In most specimens, the four unicuspids were not visible in a lateral view, but was partially visible on one side only in some specimens. Additionally, in some specimens, the dorsal foramina along the suture between the right and left frontal are partially obliterated.

Comparisons. Cryptotis evaristoi is larger and heavier, with 14 of 20 cranial measurements greater (HBL = 70–96 mm; W = 11–16 g) than C. peruviensis (HBL = 63 mm, W = 9 g). The nasal structure of C. evaristoi is narrow, the face elongated, and the inflated cranium in a dorsal view is rounded (while it is flattened in the C. peruviensis ). C. evaristoi differs from C. peruviensis by its proportional shorter tail ( Table 6 ). Compared to C. osgoodi , C. equatoris and C. montivaga , C. evaristoi has a wider nasal opening, the inflated cranium in a dorsal view is more rounded to hexagonal, and the pterygoid fossa is wider and shorter. However, C. evaristoi differs from C. equatoris and C. osgoodi by its larger size and the lighter color compared to the blackish color of C. equatoris (See table 6 for more detail comparisons). C. evaristoi differs from C. montivaga of Peru and Ecuador by its larger zygomatic plate, postorbital breadth, palatal length, the width of M1, mandibular length, and length of the articular process of M3, and M1. C. evaristoi is distinguishable from C. montivaga by its larger body size, tail, and condyle basal length; breadth of skull, postorbital, and first unicuspid, palatal length, and mandibular measurements, and the length of the unicuspids toothrow is smaller. The interorbital of the C. evaristoi is parallel in dorsal view and not convergent as in C. montivaga . The fourth unicuspid is not in line with other unicuspids, and the posterior border of the lower incisor reaches the anterior border of PM4, whereas the position is variable for the C. montivaga . The optic foramen is partially visible in a lateral view of the skull of the C. evaristoi and completely visible in C. montivaga . Compared to C. niausa , C. evaristoi is very similar in its cranial measurements but differs in body size ( Table 1 ).

Habitat. Cryptotis evaristoi inhabits the páramo and montane forest of the Tabaconas Namballe National Sanctuary. The páramo is located above 3,000 m and is characterized by vegetation adapted to extreme weather conditions such as high daily temperature variations, organic-rich volcanic soils, a high capacity for water regulation, and a high level of endemic species (Mena-Vásconez and Hofstede 2006). We conducted our study in September and October of 2009 at two localities in the SNTN. Our first study site, in the Lagunas Arrebiatadas (5° 12´S and 79° 18´W; 3,200–3,280 m above sea level), had high humidity and was representative of the Andean páramo. The dominant vegetation was herbaceous (genera Chaptalia , Dorobaea , Valeriana , Begonia, Sisyrinchum , Calamagrostis , Festuca and Neurolepis ); shrub (genera Hypericum , Desfontainia , Brachyotum , Miconia, Tibouchinia , Loricaria, Baccharis, Senecio , and Diplostephyum); and pteridophytes or vascular cryptogams (genera Huperzia, Lycopodium, Elaphoglossum, Cyathea, Blecnum , and Selaginella ). The second study site, the Miraflores (5° 12´S and 79° 12´W; 2,700–2,970 m above sea level) was characterized by elfin forest and north Andean evergreen forests consisting of thin branched trees covered with mosses and epiphytes. The dominant vegetation included sclerophyllous trees (genera Clethra , Clusia , Weinmannia , Escallonia , Hesperomeles , Gynoxys , Hedyosmum, Oreopanax and Schefflera ); shrubs (genera Baccharis, Pentacalia , Berberis, Pernnetya, Vaccinum , Bejaria , Miconia , Piper , Centropogon, Syphocampilus and Monnina ); an herbaceous layer (genera Bomarea , Anturium , Philodendrum ); and vascular plants (genera Dicksonia, Cyathea and Blecnum).

Figures

FIGURE 1. Known localities of Peruvian and Ecuadorian species of the Cryptotis genus. Records are based on Vivar et al. (1997), Moreno and Albuja (2014), and specimens observed in this study (see Appendix I for locality details).

FIGURE 8. Dorsal and ventral views of the cranium and lateral view of the cranium and mandible of Cryptotis evaristoi (MUSA 7419, paratype). Scale bar = 5 mm.

FIGURE 9. Paratype of Cryptotis evaristoi (MUSA 7412). Photograph by C.E. Medina on September 26, 2009.