Protoproviverra, LEMOINE, 1891

Solé, Floréal, Falconnet, Jocelyn & Yves, Laurent, 2014, New proviverrines (Hyaenodontida) from the early Eocene of Europe; phylogeny and ecological evolution of the Proviverrinae, Zoological Journal of the Linnean Society 171 (4), pp. 878-917 : 889-891

PROTOPROVIVERRA LEMOINE, 1891

Diagnosis

Same as for the type and only species.

Type species

Proviverra palaeonictides Lemoine, 1880 .

Type locality

MP 10, Épernay area, ‘Agéien’ ( France).

PROTOPROVIVERRA PALAEONICTIDES ( LEMOINE, 1880)

( FIG. 5 )

Emended diagnosis

This small proviverrine is characterized by a P 4 bearing an individualized paraconid and two distinct cusps on the talonid, an open trigonid on the M 1, which has a

mesially located paraconid that is lower than the metaconid, and three distinct cusps on the talonid.

Chresonymy

1880: Proviverra palaeonictides in Lemoine, p. 587; 1881: Provivera pralaeonictides [sic] in Lemoine & Aumonier, p. 613; 1891, Protoproviverra pomelii in Lemoine, p. 265, pl. X, fig. 10; 1891: Protoproviverra palaeonictides in Lemoine, p. 272, pl. X, fig. 10; 1921: Proviverra pomeli in Teilhard, p. 50; 1965: Prototomus palaeonictides in Van Valen, p. 639.

Synonymy

Protoviverra pomelii Lemoine, 1891 (objective junior synonym).

Holotype

MNHN. F.Al 5155, right mandible bearing P 4 and M 1, posterior alveolus of P 3, alveoli of M 2, and isolated P 2.

Type locality

MP 10, ‘Agéien’ ( France).

Measurements

See Table 3.

Description

The mandible of MNHN.F.AL5155 is deep, but not very robust. The posterior part is only slightly taller than the anterior part. The mandible was probably narrower anteriorly than posteriorly. A mental foramen is present under the posterior root of P 3. Ventrally, there is a mental canal.

Morlo & Habersetzer (1999: fig. 15d) considered the isolated premolar housed with the fragmentary mandible MNHN.F.AL5155, as a P 1. Its height and its pointed apex are more reminiscent of P 2 than P 1 – the P 1 is usually lower and more mesiodistally elongated than the P 2. The tooth is high and sharply pointed thanks to the protoconid. There is no paraconid. A short but wide talonid is present. It is worn, so no cusp is visible.

The P 4, which is present on the mandible, is elongated mesiodistally. A paraconid is present. It is N, number of specimens; OR, observed range. individualized, low, and elongated mesially. The protoconid is triangular and pointed in lateral view. The talonid is slightly narrower than the protoconid. The postfossid is deep. A high hypoconid is present labially. The hypoconulid, which is located distally, is lower than the hypoconid and not projected distally. A very low entoconid can be seen lingually. A short notch separates the entoconid from the hypoconulid.

On the M 1, there is a very low paraconid that projects slightly mesially. The protoconid is low. The metaconid is taller and longer than the paraconid but is only slightly lower than the protoconid. The metaconid has a strong base; it is elongated mesiodistally. Its apex is projected lingually. It is slightly more distal than the protoconid. The trigonid is robust except for the paraconid. The talonid is slightly narrower than the trigonid. The cristid obliqua is not very oblique (distally shifted labially). The postfossid is narrow and distinctly shorter than the trigonid. The three cusps are located distally. They are high and the postfossid is deep. The hypoconulid is slightly more distal, but is not well projected distally. The hypoconid is equidistant from the hypoconulid and entoconid. The hypoconid is as high as the entoconid; the hypoconulid is lower because of its wear. The cristid obliqua and entocristid are slightly oblique. The precingulid, which is located mesially, is short. This is the sole labial cingulid present on M 1. The alveoli of M 2 are visible on MNHN.F.AL5155; they indicate that this tooth is distinctly larger than the M 1.

Discussion

The ‘agéienne’ fauna was defined and described by Lemoine (1891). This fauna was distinguished from the older and more primitive Cernaysian fauna. The original ‘agéienne’ mammal fauna was collected in the area of Ay, between Reims and Epernay. However, the exact locality of the samples is unknown. Lemoine probably collected fossils in similar facies, but not of identical age ( Laurain et al., 1983; Escarguel, 1999). The majority of the taxa resemble the Cuisian mammals of the ‘Falun à Unios et Térédines’ of Avenay, whereas the remaining ones are more similar to those of the ‘Sables à Unios et Térédines’ sensu stricto. The fragmentary mandible MNHN.F.AL5155 has been assigned to the MP 10 reference level ( Morlo & Habersetzer, 1999).

The species Protoproviverra palaeonictides was originally referred to Proviverra by Lemoine in 1880, before he moved it to a new genus, Protoproviverra , in 1891. The validity of this genus was questioned by Teilhard (1921), who synonymized Protoproviverra with Proviverra . After he examined the holotype, Van Valen (1965) transferred Protoproviverra palaeonictides to Prototomus . However, it clearly differs from the other species of the genus Prototomus because its holotype MNHN.F.AL5155 has a large paraconid and entoconid on its P 4 and a wide talonid bearing an entoconid on its M 1. These features strongly support its referral to the Proviverrinae . The M 1 of MNHN.F.AL5155 differs from that of Proviverra by a combination of plesiomorphic (less developed cingulids) and apomorphic (more opened prefossid, mesially located paraconid) features. The same combination also distinguishes Protoproviverra palaeonictides from Lesmesodon , Allopterodon , and Leonhardtina .

The mesial position of the paraconid and metaconid, which results in an open prefossid, the wide and basined talonid, and the deep mandible are similar to the earliest Middle Eocene genera Cynohyaenodon , which is unusual amongst small proviverrines in having a sectorial dentition ( Lange-Badré, 1979), and Eurotherium .

The oldest species of Eurotherium is Eurotherium matthesi , which is recorded in MP 11 of Geiseltal ( Lange-Badré & Haubold, 1990). The P 4 of Protoproviverra palaeonictides and Eu. matthesi are similar in bearing an individualized paraconid and two talonid cusps. However, the M 1 of Protoproviverra palaeonictides importantly differs from that of Eu. matthesi in having a separated hypoconulid and entoconid – the closeness of the entoconid and hypoconulid is characteristic of Eurotherium ( Lange-Badré & Haubold, 1990) .

The genus Cynohyaenodon is known by two species from the Middle Eocene: Cynohyaenodon trux ( MP 12−14) and Cynohyaenodon ruetimeyeri ( MP 13−14) – the latter being the larger and more specialized ( Lange-Badré & Haubold, 1990) – and in the Late Eocene also by two species: Cynohyaenodon cailuxy ( MP 16−17a) and Cynohyaenodon lautricensis ( MP 16). The MP 10 material is intermediate in size between the two Middle Eocene Cynohyaenodon species. The P 4 is especially interesting because it enables the distinction of the two Geiseltal species. The P 4 of MNHN.F.AL5155 is more robust and is taller than in Cy. trux , but also narrow- er than in Cy. ruetimeyeri . Its M 1 is also less sectorial than in Cy. ruetimeyeri : the paraconid is less mesially located and the metaconid is more developed. These two features are significant because the mesial projection of the paraconid and the reduction of the metaconid increased during the evolution of the genus Cynohyaenodon ( Lange-Badré, 1979) .

To summarize, ‘ Proviverra palaeonictides ’ represents a valid species of Protoproviverra that is morphologically close to Eurotherium and Cynohyaenodon . These relationships have been confirmed by our phylogenetic study ( Fig. 9B ). Amongst species of Cynohyaenodon , Protoproviverra palaeonictides is closer to Cy. ruetimeyeri than to Cy. trux . Moreover, Protoproviverra exemplifies the diversity of the ecological niches occupied by proviverrines during the MP 10.

Figures

Figure 5. Protoproviverra palaeonictides (Lemoine, 1880). A−C, MNHN.F.Al5155 (holotype), right dentary with P4 and M1, posterior alveolus of P2, and alveolus of M1. A, labial view; B, occlusal view; C, lingual view. Scale bar = 10 mm.

Figure 9. Strict consensuses of the shortest trees resulting from the phylogenetic analyses of the Proviverrinae: A, first analysis, length (L) = 139, consistency index (CI) = 0.390, and retention index (RI) = 0.694; B, second analysis, L = 168, CI = 0.422, and RI = 0.754. Bremer support and bootstrap values are indicated above and below each node, respectively.