Paracricetodon Schaub, 1925

Maridet, Olivier, Codrea, Vlad A., Fărcaș, Cristina, Solomon, Alexandru A., Venczel, Márton & Tissier, Jérémy, 2025, The record of cricetid rodents across the Eocene-Oligocene transition in Transylvania, Romania: implications for the “ Grande Coupure ” at European scale, Acta Palaeontologica Polonica 70 (2), pp. 291-327 : 310-312

Genus Paracricetodon Schaub, 1925

Type species: Cricetodon spectabilis Schlosser, 1884 , Quercy (precise locality unknown), Oligocene, France .

Paracricetodon aff. Pa. stojonovici van de Weerd, de Bruijn, Marković, & Wessels, 2018

Fig. 11D–G.

Material.—One upper molar from Suceag and three lower molars from Cetățuie, Rupelian, lower Oligocene, Dâncu Formation, Gilău sedimentary area, Transylvanian Basin, Romania.

Measurements.—See Table 8. Description.—The M1 ( Fig. 11D) shows a long mesial lobe with strong anterolophs. The anterocone is transversally elontaged with a small notch on its mesial border, and with both well-developed labial and lingual anterolophs respectively reaching the paracone and the metacone. Two weakly developed spurs start distally from the anterocone, but they do not connect to any loph or cusp, so there are no anterolophule or mesial protolophule. The protocone spur is short and ends free in the anterosinus. The distal protolophule is transverse and almost straight, connecting directly the protocone to the paracone. A strong spur starts from the paracone and reaches the labial border where it merges with the metacone. The mesosinus is consequently closed whereas the sinus remains open lingually. There is no entoloph but instead the protocone is elongated and prolonged by distal arm connected directly to the hypocone. In addition to the metalophule, a spur starts from the mesial part of the hypocone and connects to the metacone, so both this spur and the metalophule surround a small pit located between the hypocone and the metacone. The posterolophid is low but long and closes the posterosinus labially. The roots are not preserved.

The m1 ( Fig. 11E) is strongly worn out but some morphological features can be observed. The anteroconid is transversally elongated and seems noticeably lower than the other cuspids. The mesosinusid is closed lingually by a large metaconid hind arm reaching the entoconid; labially the sinusid is also closed by a low but thick cingulid. There is a spur extending lingually from the entolophid into the mesosinusid; however, due to the wear it is not clear if it is a mesolophid or an mesial spur starting from the hypoconid. Despite the wear the hypoconid hind arm is clearly visible, extending into the posterosinusid. The tooth has two roots.

The two m3s have a well-developed lingual anterolophid closing the anterosinusid whereas the labial anterolophid is less developed and the protosinusid remains open. The anterolophids are connected to the protoconid by a large anterolophulid; the metalophulid is straight and connects on the anterolophulid. On one m3, the protoconid hind arm is very long and forms a loop to connect on the metalophulid delimiting a large but shallow pit between the metaconid and the protoconid ( Fig. 11F). On the other m3, the advanced stage of the wear makes it difficult to confirm similar connections between the metaconid and the protoconid ( Fig. 11G). The m3s have a short mesolophid and the spur starting mesially from the hypoconid, both ending free in the mesosinusid. The hypoconid is noticeably larger than the entoconid and they are directly connected to each other by a straight hypolophulid. The roots are preserved for one of the m3s and it has two roots.

Remarks.—This Paracricetodon is characterised by a small size and a relatively simple morphology. It is indeed the smallest Paracricetodon found in the lower Oligocene of Transylvania and among the smallest compared to all known species of Paracricetodon (see van de Weerd et al. 2018 for an exhaustive size comparison of all species of Paracricetodon ). The teeth described herein are often close to the size of Pa. stojonovici , Pa. gracilis , and Pa. wentgesi , but otherwise much smaller than all other species of Paracricetodon ( Fig. 12).

The M1 ( Fig. 11D) that was found in Suceag is characterized by a very short protocone spur without anterolophule. The short protocone spur and the absence of anterolophule can be observed in Pa. stojonovici but is absent in Pa. gracilis and in Pa. wentgesi . The M1 also has a crescent-like anterocone and no protostyle, similar to Pa. stojonovici , but as opposed to Pa. gracilis and Pa. wentgesi . The m1 from Cetățuie is similar to those of Pa. stojonovici , Pa. gracilis and Pa. wentgesi with the metaconid and entoconid situated mesially to the protoconid and hypoconid, the strong hind arm of the hypoconid and the short mesolophid. The m1 also differs from these species in having a very weakly-developed anteroconid and no ectomesolophid. The two m3s from Cetățuie have a relatively weakly-developed entoconid, similar to Pa. stojonovici , but they differ in having both short mesolophid and mesial arm of the hypoconid, and missing the ectomesolophid.

A few morphological similarities suggest an affinity with Pa. stojonovici , but the noticeable differences with all small species rather support the identification of the above-described teeth as a new species. However, the four teeth found at Suceag and Cetățuie constitute an insufficient sample to create a new species. These specimens are consequently referred to an affine form of Pa. stojonovici , waiting for more material to confirm the occurrence of a new species in the lower Oligocene of Transylvania.

Paracricetodon wentgesi de Bruijn, Ünay, Saraç, & Yïlmaz, 2003 Fig. 11H–J.

Material.—One upper molar from Mera and 2 molars from Cetățuie, Rupelian, lower Oligocene, Dâncu Formation, Gilău sedimentary area, Transylvanian Basin, Romania.

Measurements.—See Table 9. Description.—The two M1s show a long mesial lobe with an anterocone transversally elontaged and two well-developed labial and lingual anterolophs. The protostyle is present and well-developed, it has two protostyle spurs connecting to the protocone. One or two weakly developed spurs start distally from the anterocone, but they do not connect to any loph or cusp. The mesial protolophule is oblique or bent and connects to either the protocone mesial spur ( Fig. 11H) or directly to the protocone ( Fig. 11I). A strong ridge connects the paracone and the metacone on the labial border, closing the mesosinus. A short and low cingulum can be present on the border next to the paracone delimiting a little pit labially to the paracone. The sinus is also closed lingually by a low cingulum; one of the M1s also shows a low and short spur starting from this cigulum. There is no entoloph but instead the protocone is elongated and prolonged by its distal arm connected directly to the hypocone. The occurence of a mesocone suggests the possibility of a short entoloph in the continuity of the postprotocrista. In addition to the metalophule, a spur starts from the mesial part of the hypocone and end free in the mesosinus. The posteroloph is long and closes the posterosinus lingually. The roots are preserved for one of the M1s ( Fig. 11H), it has three roots.

The m3 ( Fig. 11J) has a well-developed lingual anterolophid whereas the labial anterolophid is less developed. The protosinusid is open labially, but the antero-lingual corner of the tooth is broken so the lingual extremity of the anterosinusid is not observable. The anterolophids are connected to the protoconid by a large anterolophulid; the metalophulid is straight and connects on the anterolophulid. The protoconid hind arm is strong but short and ends free in the mesosinusid; likewise, a spur starts from the junction of the distal end of the entolophid with the mesial side of the hypoconid which interpreted as a very weakly developed mesolophid. There are otherwise several very low folds of the enamel in the mesosinusid, which could be interpreted as a complex association of weakly developed spurs staring from the metalophulid, the entolophid and the hypolophulid. The hypoconid is noticeably larger than the entoconid and they are directly connected to each other by a straight hypolophulid. The posterolophid is short and thick delimiting a small and rounded posterosinusid. The tooth has two roots.

Remarks.— The teeth are slightly larger than Pa. aff. Pa. stojonovici from Transylvania and with a more complex occlusal pattern. The size of the teeth falls in the range of Pa. stojonovici or Pa. wentgesi ( Fig. 12), however, the morphology of the M1s (from Mera and Cetățuie) is very similar to Pa. wentgesi with: a short anterolophule and a well-developed anterocone, the occurrence of a protostyle connected to the protocone by spurs, the long hypocone mesial arm parallel to the anterolophule, and the so called “burgee-shaped” distal spur of the paracone (de Bruijn et al. 2003: 58) forming a continuous ectoloph connecting to the metacone (de Bruijn et al. 2003). Likewise, the m3 from Cetățuie shows a morphology close to Pa. wentgesi with: a long protocone distal arm projecting backward, a long mesial arm of the hypocone projecting forward, and a well-developed entoconid on m3. The three teeth from Mera and Cetățuie are consequently referred to Pa. wentgesi .