taxonID	type	description	language	source
3507D661B4DC52FC8EA6F9FE49C63369.taxon	diagnosis	Diagnosis. A medium-sized species of Ctenomys. Coloration ochraceous with some orange on the dorsum, with a dark patch on the dorsal snout and head, and irregular dark zones along the middle of the back; paler toward the flanks, and buff yellowish ochre on the belly. Cranial rostrum with wide base due to divergent insertion of upper incisors. Incisive foramina short, and premaxillary septum wide. Medial margins of the premaxillaries flattened against the roots of the premaxillary septum. Facial portion of the lacrimal strongly reduced and not protruding; orbital portion of lacrimal interrupted by frontal. Alveolar sheath of M 1 protruding into the lacrimal foramen, its anterodorsal portion covered by the maxillary plate posterior to the nasolacrimal canal. Edges of frontals posterior to the orbital constriction subparallel. Ventral spine of the styliform process of the auditory bulla long, especially in the living population. Tube of external auditory meatus long, especially its posterior wall. Bottom of alveolus of dp 4 and m 1 markedly protruding into the ventral portion of mandibular corpus. Masseteric crest subhorizontal.	en	Verzi, Diego H., De Santi, Nahuel A., Olivares, A. Itati, Morgan, Cecilia C., Basso, Nestor G., Brook, Federico (2023): A new species of the highly polytypic South American rodent Ctenomys increases the diversity of the magellanicus clade. Vertebrate Zoology 73: 289-312, DOI: http://dx.doi.org/10.3897/vz.73.e96656, URL: http://dx.doi.org/10.3897/vz.73.e96656
3507D661B4DC52FC8EA6F9FE49C63369.taxon	description	Description and comparison. Ctenomys pulcer sp. nov. is a medium-sized Ctenomys (measurements in Table 1), slightly larger in size than its sister species Ctenomys bidaui (see below, Parsimony and Bayesian analyses). Pelage is dense, fine and silky. The dorsal coloration is ochraceous with some orange in most specimens (Fig. 3), with individual hairs buff yellowish to ochre at their bases and with dark brown to blackish tips. A more extended blackish section in individual hairs defines a dark patch on the dorsal snout and head, and irregular dark zones along the middle of the back. The coloration is paler toward the flanks, and buff yellowish ochre on the belly where individual hairs lack the dark tips. The coloration of the tail is pale ochre with a brownish dorsal section of variable development. Forelimb hairs and ungual bristles are whitish. The cranium is similar in general shape to that of the sister species C. bidaui, but with a wider rostrum, smaller orbit, and anteriorly narrower auditory bullae (Figs 4 and 5). In the parapatric, similar-sized C. talarum, the rostrum is more expanded anteriorly, the zygomatic arches are more bowed, and the auditory bullae are less inflated (Fig. 4). The rostrum of C. pulcer has a wider base than that of C. bidaui because the incisor roots are more divergent. The interpremaxillary foramen is variable, well developed in some specimens and markedly reduced or absent in others (it is absent in the holotype MLP-Mz 8. X. 02.17; Fig. 4 A). In C. bidaui and C. talarum this foramen is always present and well developed. The premaxillary septum is wide, and the incisive foramina are slightly shorter and wider than those of C. bidaui, and shorter than those of C. talarum. The premaxillary anterior margins of the incisive foramina are dorso-medially convergent and flattened against the premaxillary septum. The palatal bridge, between the molar series, is wider than in C. bidaui. The major palatine foramina open on the maxillary at the level of M 1, as in C. bidaui. The mesopterygoid fossa reaches the level of M 2. The zygomatic arches are less bowed than those of C. bidaui. The postglenoid articular region (sensu Verzi and Olivares 2006), between the posterior border of the glenoid fossa and the external auditory meatus, is wider than that of C. bidaui, similar to that of C. talarum (Fig. 4). The auditory bullae are more inflated than those of C. talarum; they have their anterolateral portion less inflated than in C. bidaui. At the anterior end of the bulla, the ectotympanic forms an apophysis where the pterygoid process contacts the bulla (Fig. 6). This structure is ventral to the styliform process and here we refer to it as the ventral spine of the styliform process. This ventral spine attains strong development in living C. pulcer, extending markedly forward which is unique among the analyzed Ctenomys (Fig. 6). In the fossil † C. pulcer and especially in C. bidaui this apophysis is shorter. The external auditory meatus forms a more protruding tube than that of C. bidaui; especially the posterior wall of this tube is clearly longer than in C. bidaui (Figs 4 and 7). In lateral view, the cranial roof is slightly vaulted (Fig. 5), with the nasal bone more noticeably arched in some specimens as MLP 9. XII. 02.1 and MLP 9. XI. 02.2. The zygomatic arch is dorsoventrally low due to the poor development of the paraorbital process and the ventral jugal process (Fig. 5); this is a characteristic shared mainly with species of the Ctenomys mendocinus and Ctenomys magellanicus species groups. The antorbital bar is slightly more oblique, antero-dorsally, than that of C. bidaui, in which it is more vertical. The facial portion of the lacrimal bone is very small (Fig. 8), similar to that of C. australis. The orbital portion of this bone is restricted to the dorsal portion of the nasolacrimal canal by the interposition of the frontal bone (Fig. 9). Similar to C. bidaui, the first part of the nasolacrimal canal is short because the foramen into the nasolacrimal canal is close to the facial portion of the lacrimal bone (Fig. 9). Comprehensive information on lacrimal variability in Ctenomys is not available, but at least in the sample analyzed, the morphology of this bone did not show relevant intraspecific variation. As indicated by the zygomatic index, the orbit of C. pulcer is smaller than that of C. bidaui (Fig. 5; ZI in Table 1). In the medial wall of the orbit, the maxillary plate delimiting the sphenopalatine fissure covers the anterodorsal portion of the M 1 alveolar sheath, as is also the case in species of the Ctenomys mendocinus species group and C. talarum (Fig. 9). This M 1 alveolar sheath is high in relation to the level of the facial portion of lacrimal bone. In C. bidaui, the anterodorsal portion of the alveolar sheath of M 1 is exposed (Fig. 9). Similar to C. bidaui, the buccinator and masticatory foramina on the alisphenoid are mostly separated; however, this configuration is variable and in some specimens these foramina are merged into a single foramen. Both the palatine and pterygoid contact the auditory bulla, as in the other species of the Ctenomys magellanicus group and the species of the Ctenomys mendocinus group. The mastoid apophysis is short; its tip does not exceed the ventral margin of the external auditory meatus. Dorsally, the frontal margins of the orbits are subparallel, whereas these are more divergent in C. bidaui (Fig. 4). The temporal fossae are shallow as those of C. bidaui. A persistent interfrontal fontanelle is present in the holotype. There is an interparietal in adults discernible as a very short and wide ossification, similar to that of C. bidaui. The petrosal epitympanic recesses are small as in C. bidaui and wider than those of C. talarum. The lambdoid crest is slightly more developed than that of C. bidaui. As in the other species of the crown group of Ctenomys, C. pulcer has a markedly hystricognathous mandible. In dorsal view, the masseteric crest is more expanded with respect to the mandibular corpus than in C. bidaui. The origin of the masseteric crest is posteroventral to the mandibular notch (for the insertion of the tendon of the infraorbital part of the medial masseter muscle). In lateral view, this origin of the masseteric crest is more separated from the mandibular notch than in C. bidaui. The masseteric crest is subhorizontal in C. pulcer; in C. bidaui this crest is more ascending and oriented in the same direction as the ventral margin of the mandibular body (Fig. 5). Anterolaterally to the origin of the crest, the bottoms of the alveolar sheath of dp 4 and m 1 form two protuberances on the lower margin of the mandibular corpus in C. pulcer, which are more protruding than those of C. bidaui (Fig. 5). The tip of the coronoid process reaches the level of the condylar process or is below it. The chin process is well developed and located at the level of the m 1. The upper incisors have divergent insertion. They are orthodont to slightly proodont as in C. bidaui (see Proc in Table 1). The lower incisors are not inserted deeply; the bottom of their alveolar sheath and associated mandibular foramen are located further away from the condyle than in more specialized tooth-digger species such as C. leucodon, C. lewisi, or C. steinbachi (Verzi and Olivares 2006; Morgan et al. 2017). The DP 4 - M 3 / dp 4 - m 3 crowns lack cement.	en	Verzi, Diego H., De Santi, Nahuel A., Olivares, A. Itati, Morgan, Cecilia C., Basso, Nestor G., Brook, Federico (2023): A new species of the highly polytypic South American rodent Ctenomys increases the diversity of the magellanicus clade. Vertebrate Zoology 73: 289-312, DOI: http://dx.doi.org/10.3897/vz.73.e96656, URL: http://dx.doi.org/10.3897/vz.73.e96656
3507D661B4DC52FC8EA6F9FE49C63369.taxon	etymology	Etymology. From Latin Ctenomys pulcer, in Spanish hermoso (beautiful) in reference to the type locality Monte Hermoso.	en	Verzi, Diego H., De Santi, Nahuel A., Olivares, A. Itati, Morgan, Cecilia C., Basso, Nestor G., Brook, Federico (2023): A new species of the highly polytypic South American rodent Ctenomys increases the diversity of the magellanicus clade. Vertebrate Zoology 73: 289-312, DOI: http://dx.doi.org/10.3897/vz.73.e96656, URL: http://dx.doi.org/10.3897/vz.73.e96656
3507D661B4DC52FC8EA6F9FE49C63369.taxon	distribution	Distribution and habitat. Up to the present, C. pulcer sp. nov. has been found in Monte Hermoso County, in the southeastern Atlantic coast of Buenos Aires Province, in central Argentina. This area corresponds to the southernmost portion of the Pampean phytogeographic province and to the Austral Pampean district (Cabrera 1971, 1994). The predominant vegetation are grasslands that develop in a subhumid-dry climate, with a mean annual temperature of 15.4 ° C and mean annual precipitation of 684.9 mm (Cabrera 1971; Monserrat et al. 2012). In this area, C. pulcer is distributed in parapatry with C. australis and C. talarum (Fig. 2). Notably, the distribution pattern of the three species matches the three physiographic units recognized by Monserrat et al. (2012) on the basis of geomorphological characteristics and vegetation units; i. e., from shore to inland, C. australis occupies frontal active dunes, C. pulcer inhabits fixed / semifixed dunes, and C. talarum lives in more compact and humid soils at the edges of cultivated lands. This distribution was checked by conducting a 20 km shore-perpendicular transect (carried out by DHV and Eduardo Etcheverry, at midday in July 1999). C. talarum could be recognized by its vocalizations which are similar to those recorded in populations at the northern end of its distribution (DHV, pers. observ.); three specimens of this species were collected (MLP 2547, MLP 3. XII. 02.15, MLP 3028). It is noteworthy that those populations of C. talarum distributed in southern coastal localities where C. pulcer is not present, occupy the fixed / semifixed dunes (Contreras and Reig 1965; Cutrera et al. 2006). This suggests that the segregation found in Monte Hermoso precludes competition of C. talarum with the larger-sized C. pulcer (see Vassallo 1993).	en	Verzi, Diego H., De Santi, Nahuel A., Olivares, A. Itati, Morgan, Cecilia C., Basso, Nestor G., Brook, Federico (2023): A new species of the highly polytypic South American rodent Ctenomys increases the diversity of the magellanicus clade. Vertebrate Zoology 73: 289-312, DOI: http://dx.doi.org/10.3897/vz.73.e96656, URL: http://dx.doi.org/10.3897/vz.73.e96656
