Mindomys kutuku, Brito & Koch & Tinoco & Pardiñas, 2022
|
publication ID |
https://dx.doi.org/10.3897/evolsyst.6.76879 |
|
publication LSID |
lsid:zoobank.org:pub:76DA21E2-23E6-4873-8478-90B633C48A30 |
|
persistent identifier |
https://treatment.plazi.org/id/3228B2D2-6F14-4E8C-B82D-EA9FC5992731 |
|
taxon LSID |
lsid:zoobank.org:act:3228B2D2-6F14-4E8C-B82D-EA9FC5992731 |
|
treatment provided by |
|
|
scientific name |
Mindomys kutuku |
| status |
sp. nov. |
Mindomys kutuku sp. nov.
Holotype.
MECN 5809 (field number JBM 1849, Fig. 4 View Figure 4 ), an adult male specimen preserved as skull, partial postcranial skeleton, and skin in good condition; collected by Jorge Brito, Jenny Curay and Rubí García on 11 September, 2017.
Type locality.
Cordillera de Kutukú (- 2.78444°S, - 78.140000°W, [coordinates taken by GPS at the trapsite], elevation 1,925 m), Parroquia Patuca, Cantón Méndez, Provincia Morona Santiago, República del Ecuador (Fig. 5 View Figure 5 ).
Diagnosis.
A species of Mindomys smaller than M. hammondi , with opisthodont upper incisors; zygomatic notch very shallow; zygomatic plate moderately narrow and almost without upper free border; zygomatic plate frontally directed; posterior margin of the zygomatic plate anterior to M1; interorbital constriction moderately posterior and narrow; molars of absolute larger size comparatively to the skull, large jugal fully separating maxillary and squamosal portions of the zygomatic arch; hamular process of pterygoid large; alisphenoid strut present; parietal lateral “wing” reaching the zygomatic root; otic capsule medium in size; undefined hamular process of the squamosal; paraoccipital process small; well-exposed petrosal; caudally directed foramen magnum; minute Hill foramen; long incisive foramen; inferior ridge of the masseteric crest not concealing the lower margin of the dentary; lateral view of m3 not hidden by the ascending ramus; angular process of the dentary shorter than condyle; M1 broad, with anterior stylar shelf, anteroposteriorly compressed procingulum and defined anterolingual conule; M1 paracone and metacone transversally compressed; M1 accessory root present; M2 mesofosette rounded; M3 posterior lobe transversally compressed with closed metaflexus.
Morphological description of the holotype.
Dorsal fur dark reddish-brown (Fig. 6 View Figure 6 ); flanks similar to dorsum; ventral pelage pale yellow; yellowish and reddish at the edges of the gular region (Fig. 7 View Figure 7 ). Mystacial vibrissae abundant and long, some extending posteriorly beyond shoulder when laid back against cheeks; relatively small but visible pinnae on the fur of the head, naked in appearance but covered with abundant short reddish hairs. Upper side of the front and hind feet abundantly covered with brown hairs, digits covered with short, whitish hairs; the ends are each covered with a few silver hairs which protrude slightly beyond the tip of the claws; ventral surface of manus naked, with five fleshy tubercles (Fig. 8 View Figure 8 ); claws short, recurved, basally opened, except for pollex which bears a nail; pes moderately short and wide, with outer digits (1 and 5) shorter than middle three (claw of d1 extending to start of second phalange of d2, claw of d5 extending to start of second phalange of d4); plantar surface naked with six pads (2 metatarsal and 4 interdigital). Tail long (about 130% of head and body length) and unicolored (dark above and below), covered with long and hirsute hairs, which can extend up to four scales, however the hairs are sparse and give a naked appearance; tip of tail has a 5 mm tuft of hair (Fig. 7 View Figure 7 ).
Cranium with moderately long and wide rostrum (Fig. 4 View Figure 4 ); rostrum barely tapers forward from the nasolacrimal capsules; nasals gradually diverge forward, with the distal end moderately turned upwards; shallow but distinct zygomatic notches; interorbital constriction moderately posterior and narrower; fronto-parietal suture U-shaped; braincase slightly inflated and elongated; cranial roof dorsal profile flat from nasals to the half of parietals to slope gently downward toward the occiput; foramen magnum caudally oriented. Premaxillae slightly shorter than nasals not produced anteriorly beyond incisors, without forming a rostral tube; gnathic process very small; zygomatic plates moderately narrow and almost without free upper borders; zygomatic arches sturdy and robust; larger jugals; squamosal-alisphenoid groove poorly visible through the translucent braincase, without a perforation where it crosses the depression for the masticatory nerve; small stapedial foramen and carotid canal, but barely expressed petrotympanic fissure; primitive cephalic arterial supply (pattern 1 of Voss 1988); alisphenoid strut present; small anterior opening of alisphenoid canal; postglenoid foramen narrow, subsquamosal fenestra absent and undefined hamular process of squamosal; undeveloped tegmen tympani; parietal “wings” extending to zygomatic roots; small bullae with long stapedial processes; large pars flaccida of tympanic membrane present; orbicular apophysis of malleus well developed; paraoccipital process small. Small Hill foramen; long, pear-shaped incisive foramina, well anterior to the anterior faces of M1; capsular process of premaxillary little developed; palate narrow and short, with the anterior border of the mesopterygoid fossa even with the posterior faces of M3s; posterior palatal foramina small; small paired posterolateral pits located next to the anterior part of the mesopterygoid fossa; broad mesopterygoid fossa, much broader than parapterygoid plates, with V-shaped anterior margin and fully ossified bony roof; massive and projected hamular processes of pterygoids; ventrally well-exposed petrosals.
Mandible robust (Fig. 4 View Figure 4 ), with little-developed falciform coronoid process with its tip at condyle level; laterally placed mental foramen; broad incisor case; scarcely-marked higher masseteric ridge; broad condyle with well-developed pre- and postcondylid processes; alveolus of lower incisor with small capsular process on lateral mandibular surface; poorly excavated lunar notch; short and broad angular process.
Maxillary molar rows large (Fig. 9 View Figure 9 ); main cusps opposites; M1 rectangular and broad; with anterior stylar shelf, anteroposteriorly compressed procingulum and defined anterolingual conule; transversally compressed paracone and metacone; M2 mesofosette rounded; M3 posterior lobe transversally compressed with closed metaflexus. M1 four-rooted (with one accessory labial root); M2 and M3 three-rooted (Suppl. material 3).
Unusually long and wide flexids in m1-m2; procingulum of m1 not divided into labial and lingual conulids; indistinct anterolophid; mesolophid present; large posterolophid present; wide and deep protoflexid; m2 squared in outline; without internal mesofosette; mesolophid, posterolophid showing the same condition as in m1; m3 sub-triangular in outline with a deep hypoflexid; small entoflexid in line with hypoflexid. Lower molars two-rooted (Suppl. material 3).
Tuberculum of first rib articulates with transverse processes of seventh cervical and first thoracic vertebrae; second and third thoracic vertebra with differentially elongated neural spine; 19 thoracicolumbar vertebrae, the 16-17th with moderately developed anapophyses; 4 sacrals; 38 caudals, with complete hemal arches in the second and third; 12 ribs.
Distribution and remarks.
Known only from the type locality (Fig. 5 View Figure 5 ). The zoogeographic terrain in which M. kutuku was collected belongs to the eastern subtropics ( Albuja et al. 2012). The holotype was collected in evergreen montane forest of the Cordilleras Cóndor-Kutukú ( Ministerio del Ambiente del Ecuador 2013), which is characterized by trees with abundant orchids, ferns and bromeliads. The height of the emerging vegetation reaches up to 25 m. M. kutuku was collected within a mature forest near a stream (Fig. 10 View Figure 10 ). The surrounding undergrowth has a visual domain of herbaceous families such as Araceae and Melastomataceae . On the slopes, the royal palm ( Dictyocaryum lamarckianun ) predominates. The new species was collected in sympatry with the didelphids Marmosops caucae and Monodelphis adusta and the sigmodontine rodents Akodon aerosus , Chilomys sp., Hyaleamys yunganus , Nephelomys auriventer , Microryzomys minutus , Oecomys superans , Oreoryzomys balneator and Rhipidomys albujai .
Etymology.
The specific epithet is a noun in apposition after the type locality, Kutukú.
Comparisons.
The traits that clearly separate the two species of Mindomys are many and varied. Some of these features represent marked differences, such as the shape of the interorbit, the orientation of the foramen magnum (Fig. 11 View Figure 11 ), the occurrence of the alisphenoid strut (Fig. 12 View Figure 12 ), and the differential exposition of the petrosal (Fig. 12 View Figure 12 ). In addition to the characters provided in the diagnosis (see above), the molars comprise one of the anatomical systems where major differences between M. kutuku and M. hammondi are detected (Table 4 View Table 4 ).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.