Pacheco, V., E. M. Rengifo, y D. Vivas. 2014. Una nueva especie de ratón orejón del género Phyllotis Waterhouse, 1837 (Rodentia: Cricetidae) del norte del Perú. Therya 5:481-508.

Unfortunately, when originally published (Therya 5:484, August 2014) the new species name Phyllotis pearsoni was not registered in the Official Register of Zoological Nomenclature (ZooBank) and, therefore, is unavailable. The new species name is now registered as urn: lsid, zoobank.org:pub: 910F1268-625E-4D13-A6A1-3C3D6A0B1A4D and will be an available name on the date this Corrigendum is published.

Declaración de nomenclatura. Un número identificador de ciencias de la vida (LSID) se obtuvo para la nueva especie Phyllotis en: urn:lsid:zoobank.org:pub: 910F1268-625E-4D13-A6A1-3C3D6A0B1A4D.

Holotype. The holotype is an adult female specimen deposited at the Departamento de Mastozoología, Museo de Historia Natural, Universidad Nacional Mayor de San Marcos (MUSM 17431), Lima, Peru, and collected by Víctor Pacheco (original field number VPT 2397) on 01 May 2003, and prepared as skin and skull, with body preserved in ethanol.

Type locality. Campamento Callacuyán, Laguna Negra, 4,028 m, Quiruvilca District, Santiago de Chuco Province, La Libertad Department, Peru, at approximately -7° 57´ 4.5" S, 78° 14´ 14.6" W.

Paratypes. Paratypes include seven adults all deposited in the same collection (MUSM 17429, 17430, 17432, 17436-17439).

Etymology. Phyllotis pearsoni is named in honor of Oliver P. Pearson, the first mammalogist to carry out an exhaustive review of the genus Phyllotis in 1958 with his work "A taxonomic revision of the rodent genus Phyllotis", which provided the principal base for future studies; for his generosity to the senior author who received his first Sherman traps from him, and for supporting him during a visit to the MVZ collection; and last but not least for being an inspiration to the authors and numerous students of mammals.

Distribution. Phyllotis pearsoni occurs in the Puna of northern Peru, from the District of Huasmín, south of Department Cajamarca, to the District of Pallasca, north of Department Ancash. The elevational range is from 3,572 to 4,270 m.

Diagnosis. The new species is a medium-size leaf-eared mouse (TL = 203 to 249 mm) that can be distinguished from other species of Phyllotis by the following combination of characters: tail relatively short (41 to 49% of total length); anterior margin of nasals broad and spatulate, extending slightly beyond the face of the upper incisors; posteriorly, each nasal tapers to a narrow point posterior to the premaxillae and the maxilla-frontal-lacrimal juncture; zygomatic plate vertical and moderately broad with the anterior margin concave; interorbital region narrow with parallel sides and sharp edges; incisive foramina long, extending posteriorly between M1 to about half the anterocone; palate long, extending posteriorly beyond M3 by a distance of about half the length of M3 or little longer; mesopterygoid fossa U-shaped, without a medial process; squamosal ridge comparatively well developed; ectotympanic large and visible from dorsal view; M1 procingulum undivided and half-moon shaped; m1 procingulum with an anteromedian flexid; and capsular process of the lower incisors indistinct or absent.

Description. Phyllotis pearsoni has long fur, 17.0 mm in average; guard hairs as long as 23.0 mm and the pelage is soft with silky texture. The dorsum is grayish brown, the sides are somewhat more yellowish, both moderately contrasting with the venter. The hairs of dorsal pelage are slate color at the base (color 83 dark neutral grey) and tips brownish (color 26 clay in juvenile individuals or 39 cinnamon in old adult individuals). The hairs on ventral pelage are slate at the base (color 83 dark neutral grey) and tips whitish or white-yellowish. Hairs on the chin are dark gray-based with whitish tips. A pectoral streak is weakly visible or absent. Ears are large with a fine internal dark brown fur (38 tawny or 40 cinnamon-rufous) and a distinct antitragus. A small pale brown auricular patch behind the ears is present. Genal, superciliary, submental, interramal, and mystacial vibrissae are present; mystacial and superciliary vibrissae are long, but not extending posteriorly behind pinnae when laid back against head. The dorsal surface of manus is covered with fine white hairs; ungual tuft covers the claws, and the margins of the ventral surface of claws are closed at base. The digit I of manus is distinctly shorter than digit V, and this is shorter than the digit II. The hindfeet are slender and moderately long with metatarsals and digits white, heels are furred and claws are covered by long ungual tufts. Six small plantar tubercules are present. The hypothenar is smaller than and well separated from the thenar. Otherwise, the plantar surface is squamated. Digit I is very short, the claw tip extending half the length of phalanx 1 of digit II. The claw of digit V extends to the interphalangeal joint of digit IV. The tail is comparatively short, either shorter than head and body length or subequal (41 to 49 % of total length), and bicolored (dark dorsally and neutral gray ventrally); dorsal and ventral surfaces are haired, with hairs obscuring tail scales, and individual hairs extending more than 3 scale rows. The tip of the tail lacks a distinct pencil tuft. Four pairs of mammae are present in pectoral, thoracic, abdominal and inguinal position (sensu Pacheco 2003). The skull of Phyllotis pearsoni is comparatively large. The rostrum is robust and broad (in dorsal view) and moderately deep at level of the zygomatic plate (in lateral view). The nasals are long and spatulate, projecting anteriorly slightly beyond the premaxillae and the anterior surfaces of the incisors, and tapering posteriorly to a narrow point posterior to the premaxillae and the maxillary-frontal-lacrimal suture. The anterior margin of the premaxillae is short and narrow and extends beyond the incisors. The premaxillae form a pronounced ridge dorsal to the nasolacrimal foramen and just above the maxillae. The zygomatic plate is broad with the anterior margin smoothly concave, and the zygomatic notch is deep with a slightly protruding zygomatic spine. The superficial masseteric scar is small but visible and slightly behind the ventral root of the zygomatic plate. The infraorbital foramen is narrow, wider dorsally (in frontal view). The antorbital bridge is very high and lies just below the dorsal surface of the rostrum, and a large trapezoidal or squarish lacrimal attaches to it. The zygomatic arch in dorsal view is robust, with parallel sides that are weakly convergent anteriorly. The zygomatic process of the maxillae is narrow and barely wider than the antorbital bridge. The jugal is long and slender. The interorbital region is narrow, with parallel and gently squared margins, with the supraorbital foramina located slightly below. The braincase is rounded, the fronto-parietal suture is slightly serrated and U-shaped; the squamosalparietal suture is smooth with a lateral parietal process. The interparietal is small and antero-posteriorly short, with margins exhibiting indented sutures. The palatal region is long (sensu Hershkovitz 1962), slightly grooved, and extends behind the posterior plane of M3 a distance of about half or more than the length of M3. The posterolateral palatal pits are small and anterior to the mesopterygoid fossa, but behind M3s.

The diastema (in lateral view) is mainly flat. The incisive foramina are long and narrow with parallel margins. The premaxillary portion of the septum separating right and left foramina is broad and extends half the length of the foramina, while the maxillary portion of septum is long and thin. The maxillary base of the molars is broad and sub-rectangular, and clearly visible form dorsal view (sensu Pacheco 2003). The mesopterygoid fossa is narrow and U-shaped. The sphenopalatine vacuities are large and wide, exposing the presphenoid. The parapterygoid fossa is triangular and wide, with inconspicuous vacuities. The posterior opening of the alisphenoid canal is large with a distinct groove for the infraorbital artery. The middle lacerate foramen is very open, extending anteriorly beyond the level of the bony Eustachian tube; the alisphenoid extends from anterior edge of tympanic bullae to the sphenopalatine foramen, and the alar fissure is shallow. The alisphenoid strut is absent. A small anterior opening of alisphenoid canal and a long foramen oval are present. The ethmoid foramen is small and located dorsal to M2. The ethmoturbinals are of moderate size. The optic and the orbitosphenoid foramina are large and posterior to M3. The carotid circulation corresponds to the "primitive" condition (sensu Voss 1988) with a large stapedial foramen, squamosal-alisphenoid groove and a conspicuous sphenofrontal foramen. The internal carotid is moderately large and bordered by the basioccipital bone, the ectotympanic portion of the auditory bullae, and the petrosal. The ectotympanic bullae are globose. The tegmen tympani overlaps the posterior suspensory process of the squamosal and a sinus groove is present. The ectotympanic ring is closed, and the dorsal margin of the ectotympanic extends posteriorly to contact the petrosal (sensu Pacheco 2003). The ectotympanic is also large and easily visible from dorsal view. The bony Eustachian tubes are long and extend to the posterior margin of the parapterygoid fossae. The anterior process (stapedial spine) is long and slender, but does not reach the posterior margin of the alisphenoid bone. The malleus lamina is square with a long and thin manubrium; the orbicular apophysis is large and digit-like; the processus brevis of the incus is narrow with knob-like tip. The postglenoid foramen is smaller than the subsquamosal fenestra, and the two are separated by a long and narrow hamular process that reaches the mastoid bone. The lambdoid ridge is absent. The basioccipital is sub triangular and divided by a shallow medial ridge. The mastoid (periotic capsule of petrosal) is square with a moderately large fenestra. The occipital condyles are not conspicuous in dorsal view; the paraoccipital processes are small and located posterior to the hypoglossal foramen; and the foramen magnum is rounded. The hyoid apparatus is composed of an arched basihyal with an entoglossal process weakly developed, a short thyrohyal, and a ceratohyal with free and spatulated tip. The upper incisors are large and deep with moderately opisthodont orientation (sensu Hershkovitz 1962), lacking incisor grooves, and with rounded or blunt tips, the wear surface facing posteriorly. The tooth topography conforms to the tetralophodont dental pattern, with slightly hypsodont crown and cusp arrangement on M1 and m1 respectively slightly alternate and alternate. The toothrows are parallel. The anterior margin of M1 is just ventral to the posterior margin of the zygomatic plate; the procingulum is undivided and rounded, with a half-moon shape; the paraflexus and metaflexus are wider than protoflexus and mesoflexus; the paracone and metacone are slightly narrower than protocone and hypocone. M2 presents as an "S" shape, the hypoflexus is slightly deep projecting perpendicularly to the tooth and narrower than mesoflexus. M3 is 2/3 or 3/4 the size of M2, with a shallow hypoflexus and a distinct lake left by a worn metaflexus. The procingulum of m1 exhibits an anteromedian flexid and an anterior fossetid in unworn molars. In m2, the protoflexid is weakly developed or absent, the hypoflexid and mesoflexid are distinct, and a narrow and oblique posteroflexid is observed in unworn molars. The m3 is smaller than m2 but the hypoflexid and mesoflexid are conspicuous. The mandible has a slightly concave or sigmoid ventral margin. The superior and inferior masseteric crests converge in front of the anterior margin of m1; the mental foramen is high and located on the dorsal surface of diastema; the capsular process of the lower incisor alveolus is indistinct. The coronoid process is small and level with the condylar process, and the sigmoid notch between them is shallow and horizontal; the condylar process is robust, dorsal, and posterior to the angular process with a deep angular notch Phyllotis pearsoni has seven cervical, thirteen thoracic, six lumbar, four sacral and twenty-nine caudal vertebrae. The humerus has a large entepicondylar foramen and a large distinct deltoid crest; a large supratrochlear foramen is present. The calcaneum is short with a gap between the proximal edge of the trochlear process and the posterior articulation facet. The tibia and fibula are fused for more than 40 percent of the length of the tibia, and the tibia-femur ratio is 80 percent. The three middle metatarsals are longer than lateral ones (I-V). Metatarsal III is barely longer than IV and II, the metatarsal V is longer than I. The peroneal process of the fifth metatarsal does not reach the proximal edge of cuboid bone. The morphology of the stomach conforms to the unilocular-hemiglandular pattern (Carleton 1973), in which the bordering fold crosses the lesser curvature at the apex of the incisura angularis, then recurves sharply and passes to the left of the esophageal orifice. The corpus contains some glandular epithelium, similar to the figure of Thomasomys paramorum in Carleton (1973:Fig 4a). The gall bladder is present.

Karyotype, comparisons with congeners, maps of localities, tables of measurements, and illustrations of skins, skulls, dentitions along with other figures are in the original publication (Therya 5:481-508).