Cynodictis lacustris Gervais, 1852

Verger, Kévin Le, Letenneur, Charlène, Fischer, Valentin, Sánchez-Villagra, Marcelo R., Ladevèze, Sandrine & Solé, Floréal, 2025, Cranial osteology of CYnodiCtiS (Amphicyonidae), the oldest European carnivoran, Swiss Journal of Palaeontology (15) 144 (1), pp. 1-27 : 6

Cynodictis lacustris Gervais, 1852

Holotype — MNHN. F.Qu 8950, left mandible, with p2-m2, alveoli of p1 and m3.

Referred specimen — MNHN.F.Qu 17762, a cranium bearing right and left P2-M1, alveoli of I1-I3, canine, P1 and M2.

Locality —Aubrelong 1 (near Bach, Lot, France; Early Rupelian, MP 21).

Note —MNHN.F.Qu 17762 was first assigned by Filhol (1876) as belonging to Cynodictis intermedius , without further clarification, although the genus diagnosis does not include cranial characters ( Le Verger et al., 2020). Despite the absence of a mandible, the attribution of MNHN.F.Qu 17762 to Cynodictis is supported by the upper dentition with a P4 possessing a pointed and anteriorly placed protocone; an M1 with a well-developed parastyle and equally developed para-, meta-, and protocones, with a symmetrical and crescentic protocone showing pre- and post-protocristae leading to equally sized para- and metaconules, respectively, and with a strong posterolingual cingulum ( Le Verger et al., 2020). Specific-level determination is made difficult within the genus Cynodictis due to a poor upper dentition record and cranial remains known for only three or potentially four of the six/seven species that comprises the genus: Cynodictis exilis , Cynodictis lacustris , Cynodictis peignei , and potentially Cynodictis longirostris . In agreement with the synonymy envisioned by Bonis (1978) and proposed by Kotsakis (1980) of the species Cynodictis intermedius with Cynodictis lacustris , we support a taxonomic reassignment of MNHN.F.Qu 17762 to Cynodictis lacustris . Tis attribution is further supported by the presence of a more strongly pronounced accessory cusp of P3 than in the other species; a wider protocone area of P4; a wider, longer M1 stylar shelf pointing more towards the cranial midline posteriorly; a broad transverse elongation of the zygomatic arches; a vertically oriented post-tympanic process of the squamosal; an intermediate width of the tensor tympani fossa and an intermediate position of the foramina for the ramus temporalis relatively to the sagittal crest between Cynodictis exilis and Cynodictis peignei , the latter having the widest tensor tympani fossa and foramina for the ramus temporalis, the closest to the sagittal crest; a narrow and shallow external acoustic meatus; and more strongly pronounced nuchal crests.

Comparative anatomical description

Sutures. Cranial bones of MNHN.F.Qu 17762 are not always well delineated. Visible sutures are mainly towards the front of the cranium: premaxilla, maxilla, nasal, frontal, palatine, lacrimal, orbitosphenoid, pterygoid, presphenoid, jugal, squamosal (zygomatic process and post-tympanic process), petrosal, and exoccipital bones are differentiable. Te absence of some sutures, combined with complete tooth eruption and slight traces of wear on the teeth suggest that the individual was a young adult.

Dorsal view ( Fig. 2A )—Te rostrum has parallel edges,

Figures

Fig. 2 Cranium of Cynodictis lacustris MNHN.F.Qu 17762 in dorsal (A), lateral (B), and ventral (C) views.Scale bar= 1 cm. bo basioccipital, bs basisphenoid, cep carnassial embrasure pit, csm crista supramastoideus, enp entopterygoid process,eo exoccipital, fdv frontal diploic vein foramen,fm foramen magnum, fpju frontal process of jugal, fr frontal, gf glenoid fossa, ham pterygoid hamulus; iif interincisive foramen, inf incisive foramen,iof infraorbital foramen; ju jugal, lac lacrimal,M1 first upper molar, ma molar alveoli, mp mastoid process, mpf major palatine foramen, mpfr maxillary process of frontal, mpn minor palatine notch, mr molar root, mx maxilla, mxt maxillary tuberosity,na nasal, nc nuchal crest, np nasal process of nasal, oc occipital condyle, op occipital protuberance, P2-4 second to fourth upper premolars, pa parietal, pal palatine, pdp posterodorsal process of premaxilla,pgp postglenoid process, poc postorbital constriction, pop postorbital process, pp paroccipital process, pps posterior palatine spine,pmx premaxilla,pr promontorium, ps presphenoid, pt pterygoid, ptp posttympanic process, rt foramen for ramus temporalis, sc sagittal crest, sq squamosal,tc temporal crest, tf temporal fenestra, vcf ventral condyloid fossa,zpmx zygomatic process of maxilla, zpsq zygomatic process of squamosal