Protadelomys lugdunensis Hartenberger, 1969

Vianey-Liaud, Monique & Hautier, Lionel, 2022, Revision of the genus PRotadelomYS, a middle Eocene theridomyoid rodent: evolutionary and biochronological implications, Swiss Journal of Palaeontology (8) 141 (1), pp. 1-98 : 20-40

publication ID	https://doi.org/10.1186/s13358-022-00245-3
persistent identifier	https://treatment.plazi.org/id/497F1B1D-FFA1-DF19-C4B9-46C0FDF1FB39
treatment provided by	Felipe
scientific name	Protadelomys lugdunensis Hartenberger, 1969
status

Treatment

( Figs. 13 View Fig , 14 View Fig , 15 View Fig , 16 View Fig , 17 View Fig , 18 View Fig and 19 View Fig ).

Holotype. L 2627: left M1–M2; Fig. 15a View Fig .

Type locality. Lissieu (Rhône); middle Eocene, MP 14.

Original diagnosis (Hartenberger, 1969); translation from French. “Proladelomys more evolved than P. cartieri and? P. alsaticus ; lower p4 more important in the tooth row than for these two species; mesoconid always well-developed; on upper teeth sinus nearly reaching the base of the crown ”.

Emended diagnosis. Protadelomys larger than? Protadelomys alsaticus and? P. maximini ; nearly similar in size as Protadelomys cartieri . P. lugdunensis differs from P. cartieri in the higher and more robust mandible with relatively short diastema and incisor, the longer and oblique mesiobuccal to distolingual postprotocristid encompassing the mesial ectolophid and a more or less strong mesoconid, the reduced distal ectolophid, the asymmetrical sinus, which is a little deeper (reaching half height of the crown).

P. lugdunensis differs from? P. alsaticus in displaying less ornamented enamel, more bulbous cusps, simpler ridges and lophids on lower teeth, DP4 more molarized (hypocone as robust as protocone on the only one known DP 4), P4 less triangular, buccal mesoloph often longer, higher buccal protoloph and metaloph, and sinus generally marked by a higher groove (but still shallow and narrow).

P. lugdunensis differs from? P. maximini and? P. nievesae in its stronger hypocone, and in the composition of the lingual wall of the upper teeth (i.e., association of pre- and post- protocristae, protocone, endoloph, pre- and post-hypocristae, and hypocone), which is not stretched mesiodistally.

Material and measurements from Lissieu. (L: Collections of the “ Université de Lyon ”; LIS: collections of the “ Musée des confluences de Lyon ”) (Sup data, S 2). Like for P. cartieri from Egerkingen, we observed that the dimensions of upper molars in Figures 13A View Fig and 14A View Fig are more scattered than those of the lower teeth ( Table 2). Te deciduous and premolar teeth are smaller than the molars, both on the lower and upper tooth row. Te M1 and M2 are of similar size and the M3 are clearly narrower than the first two molars. Te lower m1 are moderately larger than the m2. Te m3 are longer than the m1 and m2 (see Figs. 13B View Fig , 14B View Fig ; Table 2A). All the teeth are significantly larger than those of typical? P. alsaticus ,? P. maximini , and? P. nievesae ( Table 8).

Description

Maxillary. A few maxillary fragments are represented (L45 and L45-2). Te infraorbital foramen is hystricomorphous. Te premaxilla–maxilla suture is located in front of the mesial root of the zygoma.

Upper dentition ( Figs. 15 View Fig , 16 View Fig ).

DP4. Tere is only one isolated upper deciduous premolar (LIS11, Fig. 15b View Fig ); [Te tooth n°2629 (Pl.4 Fig. 1 View Fig , in Hartenberger, 1969) is likely a P4, even if it shows a mesial buccal root oblique forwardly. Its hypocone is not lingual and quite smaller than the protocone. Te anteroflexus and anteroloph are reduced and the protoloph connects to the mesial end of the preprotocrista].

Tis DP4, moderately worn, is molariform and trapezoidal. Te hypocone is as robust as the protocone, and lingually displaced relative to the protocone. Te parastyle, standing at the same level as the paracone, is weakly swollen. Te anteroloph links lingually to the anterostyle, which connects to the short preprotocrista. Te four main cusps are bulbous. Te protoloph attaches towards the middle of the protocone. Te paraconule stretches mesially from the protoloph to the anterostyle. Te mesostyle stands at the level of the lingual flanks of the paracone and metacone; it is buccolingually compressed and stretched mesiodistally. Some isolated wrinkles form a mesoloph. Te protocone and hypocone connects through a high and short endoloph. Te sinus is very weak and low. Te metacone and the paracone are similar in size, like for P. cartieri . Te metalophule I is present but very low. It does not join the metaconule, contrary to the metalophule II, which is thicker and higher. Te metaconule is bulbous and separated from the hypocone. Te post-hypocrista connects to the posteroloph. Te thickening (worn area) observed at their junction is probably the posterocone. Te posteroflexus opens buccally.

P4. ( Fig. 15c View Fig to f). Te P4 are triangular due to the weak development of the hypocone. Te anteroloph is short and the parastyle is weakly swollen; it is free (1/4) or connected to the flank of the paracone (3/4). Te mesoflexus is narrow, buccally closed by a more or less swollen mesostyle; the latter is lengthened mesiodistally (2/4), reduced (1/4) or swollen (1/4). In L2629, the mesostyle connects to a mesoloph, which nearly reaches the metaconule level. In the other cases, the mesoloph is absent or reduced to rare wrinkles. Te paraconule is absent. Te protoloph connects to the preprotocrista (3/4) or the anteroloph (L2629). Te metalophule I is reduced or absent. Te metaconule, swollen, connects to the protocone (L45-2) or the postprotocrista (L2629). It aligns with the metacone through the metalophule II. Both are oriented towards the posterior part of the protocone, joining only on the most worn specimen (LIS13). Te hypocone is small (L45-1 and 2, L 2629, LIS13) or indistinct (LIS10), connecting the posteroloph. Te latter does not connect to the metaconule, leaving the posteroflexus opened buccally.

M1 and M2. ( Fig. 15a, f View Fig to j; Fig. 16a View Fig to e). Te crowns are unilaterally and moderately hypsodont, like in P. cartieri . Te cusps are bulbous and their apex is acute on juveniles (i.e., weakly or unworn teeth). In adults, the buccal cusps extend within the buccal parts of the protoloph and metaloph, which are slightly less high. In contrast, the lingual parts of the lophs are very low or absent. Lingually, the protocone merge within its pre-and post-protocristae, aligned mesiodistally. Te endoloph prolongs the postprotocrista mesiodistally. Te hypocone shows a similar pattern, but the pre- and post-hypocristae are shorter and weaker. Te endoloph is short and high, but lower than the apexes of the protocone and hypocone. Te sinus is barely marked; its height is less than half the crown height, and it is almost completely absent on worn teeth.

Te M1 can be quite easily distinguished from M2 due to the strong development of its parastyle, its trapezoidal outline consecutive to the lengthening of its buccal edge compared to the lingual one. On the M2, this parastyle elongates in an extension of the anteroloph. Moreover, they mostly show a metacone lingual to the paracone, so that the posterior lobe of the tooth appears narrower buccolingually than the anterior lobe, with the posteroloph being shorter than on M1.

Te anteroloph is lower and thinner than the strong anterostyle and the preprotocrista. Te paracone can be rarely divided (1/20: L45-1: Fig. 15 g View Fig ) into a bigger half displaced lingually and a stylar one developed between the end of the parastyle and the mesostyle. Te paraconule attaches to the protoloph and protrudes mesially. Te protoloph ensures the connection from the paracone to the middle of the protocone. Te mesostyle is stretched mesiodistally or bulbous. A low mesoloph reaches the level of the metaconule (9/19); it can be shorter (6/19) or absent (4/19). Te strong metaconule is slightly lower than the metacone; its position is slightly mesial to that of the metacone and hypocone. Only one specimen ( LIS5 ) displays a duplicated metaconule. Te metalophule I is always present, sometimes much reduced, lower and thinner than the metalophule II. Te latter is generally free and rarely joins the metaconule (2/20). Te metaconule weakly connects to the hypocone. Te enamel surface is generally smooth. Some rare low wrinkles are visible at the bottom of the flexi ( LIS1 , 2 , 8 , 26 ); in one case (L45-1), they are present as surface folds of the lingual flanks of the protocone and hypocone .

M3. ( Fig. 16 f View Fig to h). Te hypocone is strongly reduced. It often separates from the protocone (3/4) with a shallow sinus. On weakly worn teeth, this sinus communicates with the opposite flexus (2/4). Te paracone constitutes the only salient cusp. Te metacone is only slightly higher than the buccal ridge it forms with the mesostylar area.

(See figure on next page.)

Fig. 15 View Fig Upper teeth of Protadelomys lugdunensis Hartenberger, 1969 from Lissieu (Rhône). a L2627, left M1–M2, Holotype; a1, occlusal view; a2, lingual aspect. b LIS 11 , left DP4;b1, occlusal view; b2, lingual aspect;b3, buccal aspect. c: L2629, left P4; c1, occlusal view; c2, lingual aspect; c3, buccal aspect. d LIS 13 , right P4, occlusal view. e LIS 10 , right P4; e1, occlusal view; e2, lingual aspect; e3, buccal aspect. f LIS 45–2 , left P4–M1; f1, occlusal view; f2, buccal aspect of P4; f3, lingual aspect of P4. g L 45–1, left M1; g1, occlusal view; g2, lingual aspect; g3, buccal aspect. h LIS 14 , left M1, occlusal view. i: LIS 6 , left M1, worn; i1, occlusal view; i2, lingual aspect;i3, buccal aspect. j: LIS 22 , right M1, strongly worn; j1, occlusal view; j2, lingual aspect; j3, buccal aspect. Scale bar: 1 mm

Te paraconule and metaconule are present, although low. Te posteroloph can be either distinct from the metaconule (1/4) or connected to it (3/4).

Dentary. ( Fig. 17 View Fig ). Te body of the mandible is robust and high (L44). Te diastema and incisor are short. Te mental foramen opens close to the mesial root of p4. Te masseteric crest is strong and begins below the mesial root of m1.

Lower dentition. ( Figs. 18 View Fig , 19 View Fig ).

dp4. Only one tooth (LIS 40; Fig. 18b View Fig ), smaller than the p4, could be identified as a dp4. Its posterior buccal root is inclined distally. Te metaconid is mesiolingual. Te enamel has weak and rare wrinkles along the lingual flank of the long postmetacristid. A short mesiodistal anterolophid attaches to the metaconid. A bulged anteroconid is present buccally. A short transverse metalophulid I connects the metaconid to the protoconid, from which a low mesiodistal ridge descends in the basin. Te lophid constituted by the stretched protoconid, the postprotocristid and the mesial part of the ectolophid is weakly oblique, almost mesiodistal. Te short distal part of the ectolophid links the anterior arm of the hypoconid with the entolophid. Te latter makes an angle oriented distally at the level of a small entoconulid. Te hypoconid is higher than the hypoconulid, which is swollen. Te long posterolophid reaches the mesiolingual edge of the entoconid. A small ectostylid is present at the base of the sinusid.

p4. Te p4 is slightly shorter than m1, and clearly narrower ( Table 2A).

An anterior tooth is listed as a dp 4 in the collection from Lissieu (LIS47). However, the height and robustness of the crown and roots rather evoke a p4. Four isolated p4 (LIS 42, 37, 39, and 41) are similar in size with p4 included in dental rows (L 2625, L 2628, and LIS 44). However, the crown of LIS 41 is slightly higher than the others are and displays some peculiar features, which enable us to reattribute it to P. cartieri (see below).

LIS 32, LIS 37, and L 2625 ( Fig. 18 d, e, f View Fig ) show neither an anteroconid nor an anterolophid. Te metaconid is the only cuspid of the mesial border of the crown, which is then narrower than the other p4. On L 2628 ( Fig. 18a View Fig ), the anteroconid is buccal and isolated; a short buccal cingulid descends from the mesial end of the preprotocristid. A short mesiobuccal anterolophid is visible on L44 ( Fig. 18e View Fig ).

Te metaconid is the highest cusp of the tooth; it connects to the protoconid, which is low, weak and stretched in a mesiodistal protocristid including its pre- and post-protocristae. A very low ectocingulid sometimes interrupts an asymmetrical sinusid (LIS 32, 37, and 44). On the lingual side, the postmetacristid descends to the lingual notch. A low crestid extends from the metaconid apex to the mesoflexid; it can be continuous or not and composed of two to three very low crestules. Te mesostylid is absent. Te ectolophid is very short and distally interrupted superficially, separating the postprotocristid from the prehypocristid (LIS 37 and L44). On L 2628, the entolophid reduced to its lingual half is posteriorly oriented, connected to the mesial end of the prehypocristid. On the others, the entolophid is complete from the entoconid to the junction prehypocristid–ectolophid. Te posterolophid is well separated from the entoconid, so that the posterosynclinid opens lingually.

m1. Te m1 are smaller than the m2, the protoconid– metaconid width is lower than the hypoconid–entoconid

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Fig. 18 View Fig Lower teeth of Protadelomys lugdunensis Hartenberger, 1969 , from Lissieu (Rhône), a L2628, right p4–m3; a1, occlusal view; a2, buccal aspect. b LIS 40, left dp4; b1, occlusal view; b2, buccal aspect; b3, lingual aspect. c: LIS 32, right p4; c1, buccal aspect; c2 occlusal view; c3, lingual aspect. d L2625, right p4–m3; d1, occlusal view; d2, lingual aspect. e L44,right p4–m2; e1, occlusal view; e2, buccal aspect; e3, lingual aspect. f LIS

37, right p4; f1, occlusal view; f2, buccal aspect; f3, lingual aspect.Scale bar= 1 mm

width. Te lingual side is only slightly shallower than the buccal side. Te anteroconid is individualized on unworn or weakly worn teeth (LIS 67 and 66; Fig. 19a View Fig ,), and the anterolophid is short. Te lingual anterocingulid and the anterosinusid are weakly marked or absent. Te anterolophulid is rarely visible, mainly on worn teeth, low and connects the anterior flank of the protoconid to the anteroconid. Te metaconid represents the highest cusp, from which the postmetacristid steeply descends. Te metalophulid I is generally angled, its lingual and buccal parts distally oriented; the latter is connected to the protoconid apex. On weakly worn teeth, the enamel surface of the mesoflexid bears short mesiodistal wrinkles and granules (LIS 67, 68, and 72). Exceptionally, these wrinkles merge into longer mesiodistal ridges, which are connected to the metalophulid I (L 2628, Fig. 18a View Fig ). Te postprotocristid is thick and oblique; it extends to a more swollen area that corresponds to the mesoconid. Both are discernible on slightly worn teeth (LIS 53, 55, 67, and 68, Fig.19a, c, h View Fig ), while they appear in continuity in a long oblique lophid on more worn teeth. Some teeth have a bulbous and low anteroconid and the buccal cingulid is reduced to absent (LIS 68, 69, and 71); but their size and other features are not different of the other teeth of P. lugdunensis .

A short ridge on its lingual side indicates the mesoconid area; there is no well-individualized mesolophid. Some teeth have an ectomesolophid connected to an ectostylid (LIS 55 and L 2628), while other specimens only display an ectostylid more or less swollen (L 2625, LIS 53, 68, and perhaps on badly preserved LIS 70). Te distal part of the ectolophid is very short and low. It appears interrupted on unworn or weakly worn teeth (LIS53, 68, and 70). Te distal part of the ectolophid ensures the connection with the mesial end of the short prehypocristid and the buccal part of the entolophid. Tis buccal part is lower than the lingual one and it is partly missing on two teeth (LIS 67 and 68); both parts make a distally oriented angle. Te lingual half of the entolophid is swollen at its base, his swelling being reminiscent of an entoconulid.

Te post-hypocristid is connected to the hypoconulid; it is always well defined and higher than the posterolophid, which is short. If the lingual border of the posterosynclinid is rather high, the posterolophid itself does not merge with the entoconid. Tis cusp is lower than the hypoconid on weakly worn teeth, but the lingual side is higher than the buccal one on worn teeth: wear affects more the buccal half of the tooth than its lingual counterpart does.

m2. ( Fig. 19 e View Fig to i) Te m2 differ from the m 1 in showing a larger size, a rectangular outline due to the equal protoconid–metaconid and hypoconid–entoconid widths, a longer anterolophid and sometimes a longer anterocingulid, as well as different connections with the metalophulids. Te anteroconid is less bulbous than on the m1; the anterolophulid is lingual, often linking the anterolophid with the lingual metalophulid I, thereby forming a longer antesinusid. Other features are more similar between m1 and m2: secondary wrinkles on LIS 42, 59, 66, and 69 ( Fig. 18 View Fig ); long low mesiodistal crestids and ectomesostylid on L 2628; the presence of an ectostylid on LIS 42, 56, 57. As wear increases, the posterolophid can reach the apex of the entoconid (LIS 51, 59; L 2625 and L 2628), even on a moderately worn m2 (LIS 42).

m3. Te m3 are clearly longer than the m2 (x about 1. 15), due to the lengthening of the mesosynclinid area, they are as wide as to slightly wider as the m1 ( Table 2A). Te posterior area is narrower than the anterior one. Te lingual metalophulid I is more mesial, it is thus closer to the anterolophid (L 2628, LIS 29; Fig. 18a View Fig , 19 k View Fig ) with which it is often connected (LIS 46, 39; Fig. 19 l View Fig ). Te connection between the lingual metalophulid I and the buccal metalophulid I can be disrupted, or reduced to weak short ridges Te anterolophulid is buccal when present (LIS 29, 36, 39). Te low mesiodistal ridges arising from the buccal metalophulid I extremity are more frequent and more visible on weakly worn teeth (LIS 29, 36, 39, and L 2628). Te entoconid is reduced, which puts the metaconid in relief. Te entolophid makes an angle pointing posteriorly at the level of the entoconulid, when the latter is present (LIS49, 46). Te buccal part of the entolophid is sometimes absent (L 2625 and LIS 46). On L 2628, the apex of the angle defined by the lingual and buccal parts of the entolophid connects to the hypoconulid by a thin mesiodistal ridge; ditto for LIS 46 but the entolophid is very incomplete on this tooth. Te hypoconulid is bulged while the posterolophid is lower, short, and does not reach the entoconid.

(See figure on next page.)

Fig. 19 View Fig Lower molars of Protadelomys lugdunensis Hartenberger, 1969 , from Lissieu (Rhône), a LIS 67, right m1; a1, occlusal view; a2, buccal aspect.

b LIS 55, right m1; b1, occlusal view; b2, buccal aspect;b3, lingual aspect. c: LIS 53,left m1; c1, occlusal view; c2 buccal aspect; c3, lingual aspect. d

LIS 66, left m1?; d1, occlusal view; d2, buccal aspect; d3, lingual aspect. e LIS 56, left m1 or m2, occlusal view. f LIS 59, left m2; f1, occlusal view; f2, buccal aspect; f3, lingual aspect. g LIS 42, left m2, occlusal view. h LIS 69, left m2; h1, occlusal view; h2, buccal aspect;h3, lingual aspect. i: LIS 57, left m2, occlusal view. j: LIS 36, left m3; j1, occlusal view; j2, buccal aspect; j3, lingual aspect. k: LIS 29, right m3; k1, occlusal view; k2, buccal aspect; k3, lingual aspect. l: LIS 39, left m3; l1, occlusal view; l2, lingual aspect; l3, buccal aspect. Scale bar= 1 mm

Material referred to Protadelomys lugdunensis Hartenberger, 1969 from Egerkingen

Remarks

Together with the mandible Em 21 ( Fig. 8b View Fig , Fig. 20b View Fig ) and a few isolated molars, we tentatively refer the specimen Ek 592 (right M1–M2), identified as? Protadelomys in Hartenberger (1969) to? P. lugdunensis . Te ratio between M1 and M2 width is different from that of the holotype of cartieri in which M1 and M2 have same length, whereas here the M2 is well shorter than the M1

( Fig. 19a View Fig ), the cusps more acute and higher, and looks like the holotype of P. lugdunensis from Lissieu, LIS 2627. Among the lower teeth from Lissieu, we detected similar variation as that observed in the lower teeth of specimens previously identified as P. cartieri from Egerkingen (Hartenberger, 1969), which led us to find both species in Egerkingen and Lissieu (see below and discussion). P. cartieri is more abundant than P. lugdunensis in Egerkingen, whereas the opposite is true in Lissieu.

Material referred. Em 21, right lower jaw, with p4– m3; Ek 71, weakly worn right m2, Ek 126, right m1, Ek 72, right m3; EK 592, right M1–M2; all in Fig. 20 View Fig .

Locality. Egerkingen?α and fissure indet., upper middle Eocene ( MP 14?).

Description

Upper teeth

Ek 592, M1–M2, ( Fig. 20a View Fig ) the paracone and metacone are relatively high and acute. Te parastyle is present and swollen on M1, less on M2. Te anteroloph extends between the parastyle and the anterostyle. Te paraconule, a little less robust than the metaconule, is protruding from the protoloph, the latter being sinuous at this level. Te protoloph connects lingually at the center of the protocone. Te preprotocrista, the protocone, and the postprotocrista are aligned mesiodistally, the protocrista being relatively short and slightly separated from the anterostyle by a shallow notch. A strong mesostyle is present, linked to a thin low ridge, as a lingual mesoloph. A few low and thin extra-ridges are visible and restricted in the center of the mesoflexus. A clear but low metalophule I connects the metacone and the strong metaconule, which is mesially protruding. Te buccal part of the metalophule II, more distal, is short and high. A deep notch separates the metalophule II from the metaconule, which is free from a very short lingual spur of the metaloph visible at the level of the mid-hypocone. Te endoloph is relatively low compare to the hypocone. A shallow, narrow, and short sinus is marked between the two lingual main cusps. Te hypocone is nearly as robust as the protocone. Te posteroloph is long on M1, reaching the base of the mesiobuccal corner of the metacone. It is much shorter on M2, on which it stops at the level of the lingual end of the buccal metalophule II.

Lower jaw with p4 to m3. Te body of the mandible Em 21 ( Fig. 8b View Fig ) is wider and higher than that of Protadelomys cartieri Eg 587 ( Fig. 8a View Fig ). Te diastema is shorter and the radius of curvature of the incisor is smaller. Te mental foramen opens more distally, below the anterior root of the p4. Te masseteric crest is strong and begins below the mesial root of m1. Te incisor is thicker.

p4. ( Fig. 20b View Fig ) Te metaconid is mesiolingual and a small anteroconid is mesiobuccal, both separated by a well-marked notch. A short metalophulid connects the metaconid and a low incipient protoconid. Te posprotocristid is long and oblique, bearing a short lingual premesoconid spur. In the continuity of the posprotocristid, the ectolophid bears a stretched mesoconid, associated to a short mesolophid and ectomesolophid. Te asymmetrical sinusid (ectoflexid) is limited buccally, at its base, by a strong ectostylid. Te distal part of the ectolophid connects to the mesial end of the prehypocristid. A buccal short lophid joins more mesially this ectolophid; it corresponds to the buccal part of the entolophid of the molars. On p4, the lingual part of the entolophid turns postwardly to the junction hypoconulid–posterolophid. Te latter is short and does not join the entoconid.

Molars. m1 is a little wider than p4, and shorter and narrower than m2 and m3 (Additional file 1: S1, Fig. 3 View Fig , Table 1B). Te anteroconid extends buccally through a clear anterocingulid; it lingually joins the mesial branch of the lingual metalophulid (premetacristid). Another lingual branch, close to the former, turns posteriorly and joins the transverse buccal metalophulid I ( Fig. 20b View Fig 1 View Fig ). Te anteroflexid is defined between the anteroconid and the elements constitutive of the metalophulid I; it is limited buccally by an anterolophulid. Te metaconid is clearly higher than the entoconid, resulting in a steep postmetacristid ( Fig. 20b View Fig 3 View Fig ). One short mesiodistal spur descends in the basin located at the buccal end of the lingual metalophulid I, the enamel of which bears low and weak extra-ridges. Te postprotocristid, the ectolophid and mesoconid are in line obliquely. Te mesoconid displays two short spurs, one lingual (mesolophid) and one buccal (ectomesolophid). Like on p4, the strong ectostylid limits the sinusid buccally. Te entolophid, complete, connects to the junction ectolophid–prehypocristid. An entoconulid is more visible on m2 than on m1 and m3. Te hypoconulid is bulged at the end of the post-hypocristid, and the posterolophid is short, distinct from the entoconid, leaving the posteroflexid opened lingually.

Other lower teeth. Te m1 Ek 126, m2 Ek 71 and the m3 Ek 72 ( Fig. 20 c, d,e View Fig ) shares some features with Em 21, like the reduced or absent lingual metalophulid I, the long oblique postprotocristid bearing a more or less distinct mesoconid, an ectomesolophid, the posteroflexid closed lingually, the long postmetacristid. However, the entolophid is not connected buccally, and these teeth do not display an ectostylid. On the m?1 Ek 126, the anteroconid is connected to the preprotocristid, closing the anteroflexid buccally, whereas it is stretched and free and developed more lingually and buccally on the others. Te buccal metalophulid I is transverse on Ek 71 and Ek 72, it is oblique distobuccally on Ek 126. Te mesoconid is barely distinguishable; it corresponds to the ectolophid area located at the end of the thick oblique posprotocristid. A small mesoconid seems to be present on the m3.

Material referred to Protadelomys lugdunensis (Hartenberger, 1969) from Laprade (Tarn-et-Garonne, Quercy)

List of material and measurements: Additional file 3: S3; Te size of the teeth from Laprade does not differ significantly from that of the teeth of Protadelomys lugdunensis from Lissieu ( Tables 2, 3, 8; Fig. 21 View Fig ).

Remarks

Sudre et al. (1990) have identified the larger theridomorphs from Laprade as Protadelomys cf. lugdunensis . A smaller species was referred to Elfomys nov. sp. (Marandat et. al .. 1993; Comte et al., 2012). Here, we reassess these species and also distinguish a few teeth that could be referred to P. cartieri , and possibly another species differing from both P. lugdunensis and P. cartieri . Te co-occurrence of P. cartieri and P. lugdunensis has been reported above, both from Egerkingen and Lissieu.

Description

Maxillary. Two maxillary fragments are present in the collection ( Fig. 22 View Fig ). LAP 224 is an incomplete right hemi-maxillary, showing the alveolus of DP3; DP4 is broken and a fragment of an erupting P4 is present in the mesiobuccal alveolus; only the nearly unworn M1 is present associated with damaged alveoli of M2 and M3. Te mesial end of the zygomatic process of the maxilla is preserved, which enables to characterize the wide opening of the infra-orbitary foramen in frontal view.

In palatal view, the maxillary part of the palate is flat and wide, showing the edge for the insertion of the superficial masseter between the level of the alveolus of DP3 and the premaxillary–maxillary suture. Medial to that, there is a trace of the distal closure of the anterior palatine foramen (f.p.a.). Posteriorly, the palate is damaged, but the maxilla–palatine suture can be distinguished at the level between M1 and M2.

LAP 83 is a fragmentary left maxilla, broken at the level of the mesial alveoli of M2. On this specimen, a longer part of the zygomatic arch is preserved, showing the ridge of the insertion of the anterior deep masseter, and the posterior edge of the f.p.a.. LAP 83 shows the alveoli of P4 and a remnant of the alveolus of D3. Te only molar preserved, the M1, is more worn than those of LAP 224.

Upper teeth

DP4. Only one unworn DP4 is present in the material from Laprade (LAP 191; Fig. 23a View Fig ). It is molariform, very similar to LIS 11 from Lissieu. Because it is unworn, the anterostyle is superficially separated from the short preprotocrista. Te paraconule is displaced mesially from the protoloph. Te mesostyle weakly protrudes buccally; it is located closer to the metacone than to the paracone and associated to a weak premetacrista. A very low ridge is reminiscent of the presence of a mesoloph. Te metalophule I is weak, low, and does not join the metaconule, unlike the metalophule II, which is thicker and higher. A minute additional conule is present between the bulbous metaconule and the metacone. Te hypocone, more lingual than the protocone, is separated from the posteroloph by a shallow notch.

P4. Tere are four well preserved and two damaged P4.

A first group of three P4 is very similar to the P4 known from Lissieu. Tey (LAP 84, ( Fig. 23d View Fig ), 192 ( Fig. 23b View Fig ), 223, L 45–2) are characterized by a weak development of the hypocone. Te parastyle is absent. On a weakly worn P4 (LAP 192), the anterostyle is slightly swollen, separated from the protocone and connected to the short anteroloph. Teir mesostyle is swollen and not connected to a mesoloph. Some low wrinkles are present in the mesoflexus; they can be in line with the mesostyle forming a kind of mesoloph (LAP 84, Fig. 23d View Fig ), or directed towards the metaconule (LP 223) or the protoloph (LAP 192). Te protoloph does not reach the protocone on LAP 84, 192, and 269; LAP 223 is worn at this level. Te metalophule I is absent. Te metaconule is strong and isolated on unworn teeth (LAP 84, 192 and 269), or connected to the metacone and the hypocone on worn teeth (LAP 223).

Te two other specimens, weakly worn (LAP 235: Fig.23c View Fig , and LAP 272) display different features. Te anteroloph is much reduced and low. A short distomesial crest (anterolophule) links the buccal part of the protoloph to the anteroloph on LAP 235 ( Fig. 23c View Fig ). On both teeth, the protoloph connects to the preprotocrista. Te protoloph makes an angle pointing anteriorly at the middle of the occlusal surface of the crown. Te mesostyle is twinned, the main part being prolonged in a mesoloph directed towards middle of the mesoflexus. Te strong bulbous metaconule shows a short buccal ridge, ending free on LAP 235, and extended to the metacone mesial flank on LAP 272. On the latter, there is also a short lingual ridge, which is oblique mesially. Tese ridges may constitute remnants of the metalophule I. Te short metalophule II is distally oriented. Te P4 L45-2 from Lissieu shows a similar orientation of the short branch of the metalophule II, but the other features resemble more those of the first group of P4.

M1 and M2. ( Fig. 23e View Fig to m) Teir features are very close to those of P. lugdunensis from Lissieu. Te paracone is never divided on the M1–2 (contra in a few specimens from Lissieu: e.g., L45-1). Te paraconule is developed mesially to the protoloph. Te latter ensures the connection from the paracone to the middle of the protocone, which is bulbous at its base and pinched at its upper part from the preprotocrista to the postprotocrista. Te low mesoloph reaches the level of the metaconule (2/19); it is often shorter (15/19) and rarely absent (2/19). Te strong metaconule is swollen, a little lower than the metacone; it is slightly mesial to the metacone and hypocone.

One specimen ( LAP 196 ) displays a duplicated metaconule. Te buccal part of the metalophule I is absent or reduced to a low and short ridge. Te metaconule is sometimes more mesial; the metalophule II is directed distally from the metacone, but does not reach the posteroloph. Among these teeth, three ( LAP 85 , 86 , and 203) are a little smaller than the abovementioned specimen, but shows very similar features, with a metalophule I being well present for LAP 85 and 203 .

M3. Te hypocone is strongly reduced, separated from the protocone (LAP 206: Fig. 23n View Fig ) by a shallow sinus or connected by a low and short curved endoloph (LAP 25: Fig. 23o View Fig ).

Dentary. ( Fig. 24 View Fig ) Te body of the mandible (LAP 246) is robust and dorso-ventrally deep, as in typical P. lugdunensis . Even if the mandible is fragmentary, the preservation of a posterior part of the symphysis indicates that the diastema is short. Te mental foramen opens a little anterior to the mesial root of p4 as for typical P. lugdunensis . Te masseteric crest is strong and begins below the mesial root of m1 as for P. lugdunensis from Lissieu and P. cartier i from Egerkingen.

Lower teeth. Te lower p4, m1, and m2 are significantly larger than those of P. lugdunensis from Lissieu ( Fig. 21B View Fig ; Tables 2, 3, 8).

dp4. ( Fig. 25 a,b,c View Fig ) Tree specimens are deciduous teeth on the bases of the low crown, low profiles and shape of cusps, low ridges and diverging roots. We attributed these teeth to P. lugdunensis , even if dp4 are poorly documented in Lissieu, because the crown is higher than that of P. cartieri . Te metaconid is mesiolingual and constitutes the highest cusp. Te protoconid is low but well distinct from the metaconid due to the presence of a shallow mesiobuccal notch. A very short and low anterolophid (LAP 208—209) or anteroconid (LAP 207) limits this notch mesially.

Te sinusid is asymmetrical and short buccolingually. One slender long ridge descends from the premetacristid in the trigonid basin: it nearly reaches the bottom of the mesosynclinid. Te hypoconid, entoconid, and hypoconulid display similar height, but the latter is weakly swollen. Te entolophid is continuous, transverse, and connected to the junction ectolophid–prehypocristid. Te ectolophid is low when compared to the hypoconid. Te posterolophid is longer than that of P. cartieri (Ek 80).

p4. ( Fig. 24 a View Fig 1 View Fig ; Fig. 25 d View Fig to g) p4 are represented by four isolated teeth (LAP 210, 212, 251, and 256) and one damaged on the mandible LAP 246. Te p4 are shorter than m1 ( Table 3).

Two p4 have a reduced buccal anteroconid. Te metaconid is strong and mesiolingual. Te protoconid is poorly developed and merged in the protocristid. Te enamel shows low wrinkles along the protocristid and/ or the median crestid. Te ectolophid is weakly swollen within the mesoconid. An ectocingulid is present and long, joining the protocristid to the buccal edge of the sinusid (LAP 212: Fig. 25f View Fig ). Tere is no mesostylid. Te ectolophid is very short and interrupted shallowly, and sometimes separates the ends of the postprotocristid from the prehypocristid (LAP 251: Fig. 25g View Fig ; LAP 256: Fig. 25e View Fig ). Te orientation and position of the entolophid vary. On LAP 251, from its lingual part, a short ridge is posteriorly oriented to the hypoconulid while another ridge is directed anteriorly to the ectolophid, near the mesoconid. On LAP 256, the lingual part of the entolophid is longer and oblique postwards to the hypoconulid. A narrow, shallow slit separates this lingual part of the entolophid from its very short buccal part. On LAP 256, the low entolophid joins the extremity of the prehypocristid. Te posterolophid reaches the entoconid posterior flank, closing the posterosynclinid lingually.

m1. Te m1 are smaller than the m2 ( Fig. 21B View Fig ; Table 3) the protoconid–metaconid width is lower than the hypoconid–entoconid width. As often seen on weakly worn teeth, the lingual side is as high as the buccal side. Te anteroconid is bulbous on unworn to weakly worn teeth and the anterolophid is short. Te lingual anterocingulid and the anterosinusid are weak or absent. Te anterolophulid is low, rarely visible, mainly on worn teeth on which it connects the anterior flank of the protoconid to the anteroconid. On LAP 87 ( Fig. 26e View Fig ), a metastylid is distinct on the postmetacristid. Te buccal and lingual parts of metalophulid I often make an obtuse angle open mesially; the lingual part is weak to absent (LAP 87), distally oriented (LAP 215, 254: Fig. 25h View Fig , LAP 217: Fig. 25i View Fig , LAP 218: Fig. 26j View Fig ) or mesially (LAP 216: Fig. 25k View Fig , LAP 220); the buccal part is connected to the center of the protoconid.

On weakly worn teeth, the enamel surface of the mesoflexid bears short wrinkles and granules. Te postprocristid is oblique and extends to the mesoconid, which is swollen. Te lingual side of the mesoconid is rarely prolonged by a short edge on its lingual side. Buccally, the ectomesolophid is absent. Te short ectolophid connects together to the mesial extremity of the short prehypocristid and to the buccal end of the entolophid, which is complete. Te entolophid weakly angles at the junction of its lingual and buccal parts. Te entoconulid and the hypoconulid are more or less swollen. Te posterolophid is short.

m2. ( Fig. 26 a View Fig to d) Teir morphology is similar to that of P. lugdunensis from Lissieu, apart from their size, which is larger, and their rectangular outline due to the equal protoconid–metaconid and hypoconid–entoconid widths. Te m2 differ from m 1 in their longer anterolophid. When present, the anterolophulid has a more lingual position, often joining the anterolophid to the lingual metalophulid I, thereby forming a longer antesinusid. On LAP 249 ( Fig. 26b View Fig ), the metalophulid I is not angulated, but rectilinear and continuous from the metaconid to the protoconid; on this unworn tooth, the wrinkles and granules are numerous, but still very low. Te posterolophid is always short.

m3. ( Fig. 26 f, g, h View Fig ) Te m3 are longer and narrower than the m2 ( Table 3A). Te lingual metalophulid I is mesially oriented and joins the anterolophid. On unworn LAP 233 the buccal metalophulid I is forked, ( Fig. 26g View Fig ) a part oriented distally, like on the other m3, and a short edge oriented mesially. Te anteroconid is swollen on LAP 233 and LAP 230; it is stretched as a longer anterolophid on the other teeth. Te connection between the lingual and the buccal metalophulids is broken.

Granules are rare on the enamel surface. Te entolophid is very low; its buccal part is also very low or absent (LAP 232, 233, 252: Fig. 26 h View Fig , and 253: Fig. 26g View Fig ). Te hypoconulid is poorly inflated. Te posterolophid is short and does not reach the entoconid.