Plesiosminthus promyarion Schaub, 1930

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 : 4-5

Plesiosminthus promyarion Schaub, 1930

Type locality. Puy-de-Montdoury, MP 28, France.

Holotype. Schaub (1925) classified two m3 from Puy-de-Montdoury as? Cricetodon spec. One is extremely worn and was not described. He described the other one (Au 1214) in detail and figured it ( Schaub, 1925, plate 2, figure 10). Later, Schaub (1930) placed the two aforementioned m3 from Puy-de-Montdoury in a new species, Plesiosminthus promyarion , whose type material also includes a M2 with double protolophule from Rickenbach, Germany. Schaub (1930) did not designate a holotype. Hugueney and Vianey-Liaud (1980) designated the specimen Au 1214 as the holotype, but in fact it is a lectotype. Such type material is clearly insufficient to define a species of Plesiosminthus , or, in other words, P. promyarion is a nomen dubium in the sense of article 75.5 of the International Code of Zoological Nomenclature.

The first exhaustive description of P. promyarion is by Hugueney and Vianey-Liaud (1980). These authors recognized the insufficiency of the type material, and therefore introduced the sample from Pech Desse as reference for P. promyarion . What they did in fact was change the concept of the species P. promyarion , coining the name to a different sample. Furthermore, they placed P. bavaricus Freudenberg, 1941 from Gaimersheim, poorly known at the time, in synonymy with P. promyarion .

Since the paper by Hugueney and Vianey-Liaud (1980) our knowledge of Plesiosminthus has increased, and several new species have been described. Particularly important is the redescription of an enlarged collection from Gaimersheim by Kristkoiz (1992). That author maintained the synonymy of P. bavaricus and P. promyarion , but here we will show that the samples from Gaimersheim and Pech Desse represent different species. That means that it is impossible to know whether the type material of P. promyarion belongs to P. bavaricus or to the species from Pech Desse. The best solution is to create a new name for the Pech Desse material and restrict P. promyarion to the type material.

Hugueney and Vianey-Liaud (1980) attributed a sample from Pech-du-Fraysse to the same species as the one from Pech Desse. However, it seems to represent a different species since four of the six figured M2 from Pech-du-Fraysse have a posterior protolophule besides the anterior one. Furthermore, in Pech Desse the mesolophid of m3 is nearly always long, never absent, whereas in PDF it is shorter and may be absent. Also, the antecingulum of M1 is nearly always present in the latter locality. The width of M1 and of the lower molars is significantly larger in PDF than in PDES.

Insufficiently described samples have been reported from Ruisseau du Bey, Switzerland ( Engesser, 1987), Cournon, and La Devèze, both in France ( Hugueney and Vianey-Liaud, 1980). We provisionally refer to these samples and to the one from PDF as P. promyarion Auctorum , since it is impossible to know to what species they belong.

Plesiosminthus promyarion has been reported from Vivel del Río ( Hugueney et al., 1987). We transfer that sample to P. cf. margaritae n. sp. (see below).