Plesiosminthus moniqueae, Freudenthal & Martín-Suárez, 2017

Freudenthal, Matthijs & Martín-Suárez, Elvira, 2017, A revision of European Plesiosminthus (Rodentia, Dipodidae), and new material from the upper Oligocene of Teruel (Spain), Palaeontologia Electronica 9 (1), pp. 1-25 : 5

Plesiosminthus moniqueae n. sp.

zoobank.org/ 0154335C-6C9E-4F15-9ABD-3C64C0CECFF7

Type locality. Pech Desse, MP 28, Quercy , France. Holotype. M2 sin., PDS 510, Hugueney and Vianey-Liaud (1980, plate 4g).

Measurements. Appendix 1 (from Hugueney and Vianey-Liaud, 1980).

Derivatio nominis. In honour of Dr. Monique Vianey-Liaud, co-author of the first monographic paper on Plesiosminthus after the study by Schaub (1930).

Diagnosis. Based on data in Hugueney and Vianey-Liaud (1980); In m1 the anteroconid is isolated and the mesostylid is well developed; the ectolophid is rarely interrupted at the protoconid. In m2 the protoconid hind arm (or posterior metalophulid) is complete in 30%, absent in about 20% of the specimens, and incomplete in the rest; in m3 it is absent in about 30% and complete or incomplete in the rest. M1 and M2 almost equal in length. In M1 the mesostyle is well developed; in 33% of the specimens, there is an anterostyle and a cingulum in front of the anteroloph. In M2 the protolophule is anterior and a posterior connection is rarely present.

Differential diagnosis. Plesiosminthus moniqueae n. sp. from Pech Desse differs from most other species (except for P. schaubi and P. admyarion ) by the rarely present posterior protolophule in M2 (morphology value MV = 0.195; see Table 3 and Figure 2 ). It differs from P. schaubi and P. admyarion by its smaller size.

Figures

FIGURE 2. Distribution of morphology values of protoconid hind arm in m2 (filled circles) and protolophule in M2 (open circles). Enclosing circles and connecting lines indicate possible relationships.