Cymbalophus aff. cuniculus (Owen, 1842)

Bronnert, Constance & Métais, Grégoire, 2023, Early Eocene hippomorph perissodactyls (Mammalia) from the Paris Basin, Geodiversitas 45 (9), pp. 277-326 : 287-288

Cymbalophus aff. cuniculus

( Fig. 6B )

MATERIAL. — m3 (R: MNHN-MU12263 [broken]; L: MNHN-CB1597 ) .

DISTRIBUTION. — Mutigny, Condé-en-Brie (MP8+9).

DESCRIPTION

m3 from Mutigny

The tooth is worn and broken, only the talonid is preserved. The hypoconulid lobe is very short.

m3 from Condé-en-Brie ( Fig. 6B )

The metaconid is not twinned.The lophs are high and well developed. The protolophid is more notched than the hypolophid. The hypoconulid is small, the hypoconulid lobe is very short. A postcristid links the hypoconid to the hypoconulid. The cristid obliqua is oriented toward the middle of the protolophid.

COMPARISONS

The teeth have the same proportion as those of C. cuniculus . The protolophid is less developed than in C. cuniculus , and the cristid obliqua is slightly more lingual. The cristid obliqua ends higher on the protolophid than in C. aff. cuniculus from Rians ( Godinot 1981). The paralophid is much shorter than in C. aff. cuniculus from Rians.

COMMENT

The dental morphology is very similar to that of C. cuniculus , except for the more lingually directed cristid obliqua which is a derived feature. However, such a character could be intraspecific variation ( C. cuniculus is not well known), or temporal and/or geographic variation within a population. The fossil record of Cymbalophus is very scarce as this genus has been recorded only from localities close to the MP7. The discovery of specimens in Condé-en-Brie and Mutigny (MP8-9) extends its range, and this allows to assume some morphological variation of the species through time. Nevertheless, considering the few fossils discovered for this species in these MP8-9 localities, and particularly in Prémontré (MP10) which has yielded a large number of specimens, we do not exclude that this is an extreme and poorly represented variation of Orolophus maldani , which is widespread in these deposits.

Figures

FIG. 6. — Teeth of Cymbalophus cuniculus (Owen, 1842) from Erquelinnes and Kyson, and C. aff. cuniculus from Condé-en-Brie in occlusal view; A, mandibular symphysis (IRSNB-M-167); B, right m3 (MNHN-CB1597); C, right m3 (BMNH-14113); D, left P3 (BMNH-36572); E, left M3 (lectotype, BMNH-36569); F, left p3- m2 (IRSNB-M-167); G, right m3 (BMNH-29710). B, coated with magnesium. Scale bar: 5 mm. Photo credits A, C-G, C. Bronnert.