Protadelomys alsaticus, Vianey-Liaud & Hautier, 2022

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 : 43-57

? Protadelomys alsaticus differs from:

- Protadelomys cartieri in a few ancestral features as the sometimes slightly more reduced hypocone, the P4 shorter relative to M1, or the presence of a mesoconid.? P. alsaticus also displays more numerous specialized characters such as the small hypocone frequent on P4; the buccal mesoloph longer, the strong metaconule more protruding in the mesoflexus, the thick high endoloph on upper molars; the protoconid stronger on dp4 with the entolophid connected to the prehypocristid + ectolophid on lower molars.

- Protadelomys lugdunensis in the absence of anterocingulid on lower teeth, and the enamel ornamentations more numerous and frequent.

-? Protadelomys maximini in the often longer and more frequent mesoloph, the less reduced hypocone, and the thicker lingual wall.

- Tardenomys . On upper teeth: In the constant presence of a high endoloph, a thick prehypocrista and well-distinct metaconule, isolated from the hypocone; in the absence of a fully developed mure. On lower teeth: in the less frequent and weaker oblique extra-ridge from the lingual extremity of the buccal metalophulid I, and in the absence of buccal cingulid developed from the anterolophid together with the buccal closing of the anteroflexid.

Material and measurements: (Additional file 4: S4, Table 4A). Numerous isolated teeth (6 DP4, 11 P4, 69 M1–M2, 21 M3; 9 dp4, 9 p 4, 64 m 1 and m 2, 21 m 3) come from the green marls at the base of the Bouxwiller Quarry. Most of the teeth belong to the species? P. alsaticus here revised. Tey are provisionally attributed to the paraphyletic genus? Protadelomys . Te congruence between the size and some morphological features makes it possible to distinguish several morphotypes within the assemblage from Bouxwiller that are plotted on the Figure 27 (morphotype 1: light violet; morphotype 2. turquoise; morphotype 3: light green). Like for P. cartieri and P. lugdunensis ? P. alsaticus displays DP4, P4, dp4 and p4 smaller than the molars. M1 and M2 are similar in size and the M3 are clearly narrower than the other molars, but are close in length. Te m1 are moderately smaller than the m2. Te m3 are longer than the m1 and m2, but less than in P. lugdunensis . Te teeth are a slightly smaller than P. cartieri

( Fig. 28 ; Tables 1, 4), and significantly smaller than P. lugdunensis ( Table 8).

Description. Most of the teeth bear more or less low additional ridges and granules, and the enamel surface of the crown displays faint and oriented ornamentations from the base to the edge of the crowns, which are mainly lingual for upper teeth and buccal for lower teeth.

Description of the type (BUX67-2) ( Fig. 31a ).

Te type specimen corresponds to an M2 that displays a long and thin buccolingual anteroloph, in the extension of a thick and high preprotocrista, swollen at is mesial extremity in an anterostyle. Te bulged paracone and metacone are similar in size. Te buccal part of the protoloph is straight, until its low connection to the paraconule. Te latter is bulged and protruding mesially from the protoloph. Lingually to the paraconule, the very thin and low lingual part of the protoloph weakly connects the apex of the protocone. A thin postparacrista and a thicker premetacrista are present and descend towards but do not fuse with the bulged mesostyle. Te latter prolongs lingually in a buccal mesoloph, for which the distal end faces but does not fuse with the metaconule. Te buccal metalophule II is strong, first parallel to the buccal protoloph, then turns mesially; it joins a high distolingually to distobuccally stretched metaconule, which reaches the center of the tooth. Several extra-ridges descend mesially from the buccal protoloph and the metalophule II, around the mesiobuccal extremity of the metaconule, and on the buccal flank of the association of the protocone and endoloph. Te metalophule I is not distinct among these extraridges. Te hypocone is nearly equal in size to the protocone; both cusps are a little stretched, mesiodistally for the protocone and mesiolingual to distobuccal for the hypocone. Tis stretching of the protocone and hypocone prolongs in their anterior and posterior arms. Te metaconule is stretched and prolonged mesiobuccally to distolingually to join the hypocone via a high lingual metaloph. Te postprotocrista and prehypocrista are short and linked by a thick and high endoloph. Te posteroloph is short and lowly connected to a short post-hypocrista; it begins lingually in a bulged posteroconule, and ends at the base of the metacone, the posteroflexus being opened buccally.

Upper teeth. Te teeth of P. alsaticus are unilaterally and weakly hypsodont. Tereby, the occlusal surfaces vary with wear, but not strongly. Te cusps are bulged; the conules and associated ridges are sharp on unworn teeth, but blunt and rounded on worn teeth. Te breaks along the lophs as well as the extra-ridges and granules sometimes disappear with wear.

DP4 ( Fig. 29a to d). Eight teeth correspond to DP 4 in our sample; among them six only are referred to this species, and the two largest (CSBX2 and 3) to? Protadelomys cf. alsaticus morphotype3. In all cases, DP4 are smaller than P4 ( Fig. 27 A ; Table 4A). Teir contour is triangular due to the presence of a small hypocone.

Te parastyle is present and the anteroloph relatively long and low. Te anteroloph links with the preprotocrista. Te anterostyle is not clearly distinct, due to wear. Te paraconule is smaller than the metaconule and slightly protruding from the protoloph, the latter being weakly linked to the preprotocrista. Te mesostyle is slightly more buccal than the paracone and metacone; it is closer to the metacone and is separated or connected to a short mesoloph. Te metalophule I is sometimes absent, often present but short, low, discontinuous, directed or connected to the mediobuccal crest of the metaconule. Te metaconule is strong, isolated from the hypocone, and weakly connected to the postprotocristid. Te hypocone is conical and much smaller than the protocone; it is lingual when compared to the protocone. Te endoloph is very short and high. Te sinus is absent or barely marked. Te posteroloph is generally short and swollen at the level of the posteroconule. Te hypocone– posteroloph connection is either low and short, or weak or absent.

P4 ( Fig. 29e to l). Tirteen teeth correspond to P4. On a length x width diagram ( Fig. 27 ), two groups are identifiable. Te first gathers the longest and narrowest teeth (CSBX5, 6, 7, 8, 9), and the second the shortest and longest ones. However, their morphological variation is partly independent of this grouping. Moreover, their lengths and widths show a coefficient of variation v compatible with a single population ( Table 4A) ( Legendre & Vianey-Liaud, 1986). Among the largest P4, CSBX8 is morphologically simpler and can be referred to? Protadelomys cf. alsaticus morphotype 1; CSBX12 displays a sharp and strong preparacrista and a mesoflexus closed buccally, it can be referred to? Protadelomys cf. alsaticus morphotype 3. All the other P4 are attributed to? Protadelomys alsaticus .

All P4 are triangular with a reduced hypocone (12/13). Only CSBX 9 displays a hypocone nearly as strong as the protocone; it is more squared, with parallel anteroloph and posteroloph but its other features are similar to those of the other P4 ( Fig. 29i ). Te endoloph is very short to absent, and the sinus is generally absent or barely marked. Te paracone is isolated (9/13) or lowly connected to the paraconule (4/13). Te anteroloph is very short and slender. Te paraconule is generally indistinct from the anterostyle, as a strong mesiolingual conule, lower than the paracone and protocone. Te mesostyle prolongs in a mesoloph; on CSBX 6 ( Fig. 29f ) the buccal openings of the mesoflexus, on either sides of the mesostyle, are blocked by short ectocingulids. A premetacrista is generally present. Te metalophule I is short and weak. Te metaconule is strong, isolated from the lingual cusp on the less worn P4 and, on the others, it is connected either to the postprotocrista by a very low ridge on CSBX 7, 9, 12, or to the hypocone (CSBX 13, 29) or to the posteroloph (CSBX 28). Te strong bulbous metaconule bears a short mesiobuccal ridge, ending free or connected to the metalophule I. Tere are more or less numerous low extra-ridges or granules in the mesoflexus.

M1 ( Fig. 30 ) and M2 ( Fig. 31 ). If M1 and M2 display a strong morphological variability, a common pattern is recognizable. All these teeth are pentalophodont, with a short mesoloph. Te paracone and metacone are salient; the protocone and hypocone are sharp on weakly worn teeth and blunt when worn. Te protocone is stretched mesiodistally with its pre- and post-protocristae. Te hypocone is smaller than the protocone, with lower and weaker arms. Mesiodistally, the endoloph is short, thick, and high but a little lower than the protocone and hypocone summits (as seen on lingual views of unworn teeth; Fig. 30a 2, b2 , c 3 , f 2 ). Te sinus is barely marked or absent. Te paraconule is protruding mesially from the protoloph; it is rounded or a little stretched distomesially, and generally nearly as strong as the metaconule. Te metaconule is generally more bulbous than the paraconule, except on the holotype where it is stretched obliquely. Te connection between the protoloph and the center of the protocone, as well as the connection between the metaconule and the prehypocrista, are generally weak and very low, except on the holotype. Te buccal metaloph is generally absent, the metaconule being separated from the hypocone.

Te main variation involves the development of the parastyle and anterostyle, the shape and thickness of the mesostyle, the length and development of the mesoloph, the relationships of the latter with the mediobuccal crest of the metaconule, the development of metalophule I, the connection between the metaconule and the posteroconule, the extra-ridges and granules, and the enamel ornamentation. Te parastyle is often more swollen on M1 than on M2, but not always. It generally fuses with the anteroloph; except on some unworn specimens like CSBX 67: Fig. 30b , CH 41: Fig. 30c , BUX 67–28, and BUX 67–54: Fig. 30h . Te anteroloph is higher than the posteroloph and located between the parastyle and the anterostyle. Te latter is generally swollen and connected to the end of the preprotocrista, which is more or less oblique linguo-mesially. On BUX 67–61: Fig. 30f , the preprotocrista is slightly mesiodistally oriented. Te anteroloph is more or less crenulated, with very short mesiodistal wrinkles. One of these wrinkles sometimes joins an extra-ridge from the protoloph. Tis extra-ridge can be present, absent, or duplicated and parallel to the paraconule. Te distal flank of the paracone rarely shows a short postparacrista (M1: BUX 67–61: Fig; 30f, BUX 67–54: Fig. 30h CH 49, Fig. 30l; M 2 : BUX 67–44: Fig. 31e , BUX 67–2, BUX67-56: Fig; 31I, CSBX 36). Te premetacrista is thick and always present. Te metalophule II is short and rarely connected to the metaconule. Te metalophule I is absent or reduced to weak extraridges. Te surface of the mesostyle can be underlined by a hawkshape ridge (BUX 67–59, 64), which disappears with wear in a thick mesostyle. Short mesiodistal ectocinguli rarely frame the mesostyle ( Fig. 30d ). When present, the granules and short low extra-ridges are located in the mesoflexus, from the base of the protocone to the mesoloph and metaconule. Te mediobuccal crest of the metaconule is generally weak, and sometimes directed towards the lingual extremity of the mesoloph, without merging with it. BUX 67–70 departs from other molars by its more triangular shape. It probably corresponds to an M1, as the posteroloph and the hypocone are not really reduced. Te preprotocrista is relatively short and the anterostyle small. Te parastyle is not salient. Te protruding paraconule is small. All the other features are close to those described above.

On the M2 CSBX 30, the post-hypocrista is absent and the posteroconule is linked to a short lingual part of the metaloph, which descends from the hypocone; the posteroloph is reduced to a short crest.

M3. ( Fig. 32 ). Most of the M3 are unworn or weakly worn (17/21); they display a wide range of size variation

( Fig. 27 A ), but their lengths and widths show a coefficient of variation v compatible with a single population ( Table 4A) ( Legendre & Vianey-Liaud, 1986). Among the three biggest teeth, BUX 67–27 could belong to? Protadelomys cf. alsaticus morphotype 3. We have not found singularities for the two other large M3 (BUX 67–85, 86), which could justify to exclude an attribution to? Protadelomys alsaticus . Among the smallest specimens, BUX 67–88 and BUX 67–87 are referred to? Protadelomys cf. alsaticus morphotype 2.

Te remaining 18 specimens display a long anteroloph and a distinct parastyle. Te paracone represents the higher cusp. Te metacone is salient from the buccal ridge it forms with the mesostylar area and the metalophule II. Te paraconule is small and protruding. Te development of the metaconule is variable; it is salient on unworn teeth and otherwise usually weaker than the paraconule, but not always ( BUX67-84 ). Te central basin is wide and filled with extra-ridges as strong as in the M1–2, in the area close to the mesostyle and metaconule. Tese extra-ridges are more or less numerous. Te distal part of the teeth is highly variable. Te metalophule II is short, connected to the metacone and oriented distomesially. It can be separated from the metacone or absent, with the metacone connecting with the posteroloph. Te hypocone, more or less strongly reduced, is more buccal than the protocone. Te posteroloph always joins the post-hypocrista. Te sinus is often present but weakly marked; it rarely communicates with the opposite synclines. Wrinkles can be present on the lingual slope of the crown .

Lower teeth. ( Figs. 33 , 34 , 35 , 36 , 37 ) six specimens are considered as dp4 of? Protadelomys alsaticus . Te size distribution ( Fig. 27 B ; Table 4A) is large, dp4 being the smallest, then p4 smaller than molars, the m2 being slightly larger than the m1. Te crowns of all the teeth are as high buccally as lingually, but their lingual flank is relatively flat whereas the buccal flanks of the protoconid and hypoconid are bulged. Wrinkles, weak ridges or granules are variably present in the basins.

dp4. ( Fig. 33a to f) Te metaconid is the highest and mesial-most cusp. It separates from the protoconid, which is smaller. Te anteroconid is absent; a weak and short mesiobuccal ridge (preprotocristid) is only visible on two teeth ( CSBX 50 : Fig. 33f , and BW 56–55; Fig. 33e ). A short buccal metalophulid I is only visible on CH 55. Te metaconid prolongs distally in a high postmetacristid. A small mesostylid is isolated at the distal extremity of this crest on two specimens ( CSBX 50 and BW 56–54 ). All specimens display a low mesiodistal extra-ridge, descending from the metaconid to the mesoflexid. Tis extra-ridge is high on CSBX 43 ( Fig. 33a ) less on the others, discontinuous on CSBX 50 , CH 55 and BW 56–55, and almost erased on BW 56–54. Tere are a few granules and/or low ridges in the basins (meso- and posteroflexids). Te postprotocristid is nearly mesiodistal and connected to the mesoconid; the latter is a little swollen and the ectolophid can be more lingually located, after making an angle distal to the mesoconid ( CSBX 43 ). Tis ectolophid lowers between the mesoconid and the short prehypocristid. Te entoconid is salient and isolated from the postmetacristid–mesostylid. Te entolophid is complete and very low (6/9), joining the extremity of the short prehypocristid; it is incomplete on BUX 67–100 and 104. On one specimen only ( CSBX 43 ), the lingual half of the entolophid is distally directed towards the posterolophid. Te hypoconulid is swollen and connected to a long post-hypocristid and to a short posterolophid. Te latter ends at the level of the distal flank of the entoconid, and closes the posteroflexid lingually .

p4. ( Fig. 33g to m) Te posterior root of p4 is vertical and strong. Te length between the entolophid and the mesial border is only a little longer than to the distal bor- der; it is shorter than in the other Protadelomys species. Te metaconid is the highest and mesial-most cusp, and extends in a long lingual postmetacristid. Te metaconid separates from the protoconid, which is smaller and weaker. Te protoconid is usually low and less distinct than that of dp4; it is rarely well distinct from the metaconid ( CH 26, BW 56–57, and BUX 67–97). Te anteroconid is absent; there is only a weak short mesiobuccal ridge on BW 56–55, and a shallow anterosinus on BUX 67–103

( Fig. 33k ). Te wrinkling of the enamel is stronger on the latter than on the other eight p4. Te mesiodistal ridge is usually low, continuous or more or less interrupted. Te granules and extra-ridges are rare. BUX 67–103 and 107 are the most ornamented p4. Te mesoconid is weak, the mesial ectolophid is indistinct from the postprotocristid– mesoconid, and the distal ectolophid is short and broken at the level of the prehypocristid, as seen on unworn or weakly worn teeth ( CH 26: Fig. 33g ; BW59-57: Fig. 33h ). An ectostylid is present buccally at the base of the sinusid on BUX 67–101 and 103. Te sinusid is asymmetrical and pinched. Te entolophid is low and rarely continuous (BUX 67–103 and 105), directed to or connected to the short prehypocristid. Te hypoconulid is not well individualized; the posterolophid ends at the base of the entoconid.

m1 ( Fig. 34 ) -m2. ( Fig. 35 ). Te two loci can be distinguished by a set of morphological characters. Te hypoconid is as strong as the protoconid, and slightly placed more buccally on m1 than on m2. Te distal root is generally more vertical on m1 than on m2, where it is oblique posteriorly and a little twisted buccally. On m1, the metaconid–protoconid width is lower than the entoconid–hypoconid width, the anteroconid is usually less stretched and shorter, and the anterolophid is most often absent.

For both m1 and m2, the morphological variation is important. We did not identify clear-cut groupings among the molars, but by combining size variation and a few discrete features, a characterization of three different tooth morphotypes was made possible (see below).

On all m1 and m2, the metaconid is the higher cusp, followed lingually by a high and strong postmetacristid descending more or less steeply towards the lingual opening of the mesoflexid. Te mesostylid is absent on the m1, except on CSBX 48, and present on a few m2 as a swelling at the distal end of the postmetacristid (BSK-A28, BUX 67–110: Fig. 35 h , 127: Fig. 35d , 132,?134, BUX 68–44: Fig. 35k ) or as a separated small cuspid (BUX 67–116, CSBX 46). Te valley between the postmetacristid and the entoconid is generally obtuse but it appears more constricted, acute, on BUX 67–136, 137, CSBX 47, and BUX 68–33, or even reduced when the mesostylid is present. An anterolophid is present, as a short lingual prolongation of the anteroconid, on m1 BUX 136 only. On m2, the anteroconid is generally slightly bulbous, more or less stretched buccolingually. It disappears in the slender anterolophid on BUX 68–44 and 46, BUX 67–112: Fig. 35f , 117, 118, and 141. On BUX 67–141, the anterolophid is longer than on the other m2, whereas the thick lingual metalophulid I is not mesial and runs obliquely (mesiobuccally) from the top of the metaconid to meet the transverse buccal metalophulid I. Te complete metalophulid I usually closes the anteroflexid distally (m1: BUX 67–25, CSBX 67–52; m2: BUX 67–110: Fig. 35 h , 116, 119: Fig. 35i , 120) at least at its base; but sometimes it is open distally when the connection does not exist (m1: BUX 68–33, 39; CSBX 42, BUX 67–11; m2: BSK-A21, A28; BUX 67–15, 112: Fig. 35f , 118, 121, 139; CH 13; CSBX 49). Te anteroflexid is reduced when the lingual metalophulid I is mesial, as a premetacristid (m2: BUX 67–19 and 133). Te anteroflexid is slightly opened buccally on weakly worn teeth, but a low buccal elevation of enamel is present on its floor.

If the buccal half of the metalophulid I always retains the same cuspid arrangement and buccolingual orientation, a strong variation is observed on the lingual metalophulid I. Te buccal metalophulid I always starts from the apex of the protoconid to run linguobuccally towards the midwidth of the crown. Te main variation occurs at the connection with the lingual metalophulid I. Tey generally separates with a mesiodistal narrow groove, more or less wide or deep. In these cases, the lingual metalophulid I can be short and regularly thin (e.g., BUX67-33: Fig. 35l ) or thick (e.g., 130: Fig. 35c , 132: Fig. 35b , 133, 141; CH 22), or bulbous at its buccal end (e.g., BUX 68–39; BUX 67–129). Te lingual and buccal parts of the metalophulid I can, in some cases (CSBX 40, 44, 46, 52; BUX 67- 113, 132, 140), be strongly connected.

Te lingual metalophulid I is usually mesial, and occupies the position of the premetacristid (e.g., m1: BUX 68–39; BSK-A24, 25, 27; BUX 67–25, 114, 128, 135, 136, CSBX48; m2: BUX 67–110, 112, 113, 116, 117, 120, 133, 140; BUX 98–44; BSK-A21, A28, A29; CSBX 40, 41, 49, 53). It can be slightly displaced or angled distally (m2: BUX67-11, 15, 115, 121,132, 134; BSK-A26; CSBX 42, 46, 47, 54), or splitted in two branches more or less separated (e.g., m1: BSK-A22; BUX 67–5, 19; BW 56–59; CH 13, 17, 24; CSBX 44, 52, 56; m2: BUX 67–127, 130). On BUX 67–141, the strong lingual metalophulid I is transversely in line with the buccal metalophulid I. When distinct from the buccal metalophulid I, the lingual metalophulid I can be long (half-width of the metalophulid I length) or short (e.g., m1: BUX 67–115, 123; CH 22; m2: CSBX 54; BUX 67–115). Te overall shape of the lingual and buccal metalophulids I makes an angle open mesially (e.g., BUX 67–124, 126, 132, 140; CSBX 46), but it can be

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Fig. 34 Lower m1 of? Protadelomys alsaticus Hartenberger, 1969 from Bouxwiller (Bas-Rhin). a BUX67-136, right m1; a1, occlusal view; a2,buccal aspect; a3,lingual aspect. b CSBX52, left m1; b1, occlusal view; b2, buccal aspect. c: BUX67-135, left m1; c1, occlusal view; c2, buccal aspect; c3, lingual aspect. d BUX68-39,right m1; d1, buccal aspect; d2, lingual aspect; d3, occlusal view. e BUX67-5, left m1; e1, occlusal view; e2, buccal aspect; e3, lingual aspect. f BUX68-33, right m1; f1, occlusal view; f2, buccal aspect. g BUX67-128, left m1; g1, buccal aspect,; g2, occlusal view; g3, lingual aspect. h CH 22, left m1; h1, occlusal view; h2, buccal aspect. i BSK-A24,left p4; i1, occlusal view; i2, buccal aspect. j: BUX67-111, right m1; j1, occlusal view; j2, buccal aspect;j3, lingual aspect. k: BUX67-114, right m1; k1, occlusal view; k2, buccal aspect; k3, lingual aspect. l: BUX67-115, right m1; l1, occlusal view; l2, buccal aspect.Scale bar = 1 mm

strictly transverse (e.g., BUX 67–113, 131, CSBX 44, 52). hypoconulid), and even ridges (posterolophid and extra- A lower and generally weaker ridge descends from the ridges), which are all thick and low. Te mesial part of apex of the metaconid, distally to the main lingual metal- the ectolophid is mesiodistally oriented and very short ophulid I (CSBX41, 47, 48; BSK-A21, A29; BUX 67- 127, and weak; its distal part is directed buccolingually to con- 128, 130, 135, 136, 140; CH 17, 22). It is generally slen- nect the postmesoconid, and is linked to the extremity of der, weak, and short, but can also be absent. In few cases, the prehypocristid. In only a few cases (BUX 67–19 and the connection of this ridge with the buccal metalophulid CSBX 52), the mesolophid is facing the lingual flank of I occurs through this distal lingual metalophulid I. It is the mesoconid, and is reduced to a spur. Te other molars the case for instance on BUX 67–25,123, where the met- do not show a true mesolophid. A postmesolophid-like alophulid I is complete and angles medially; or on BUX structure is sometimes visible (BUX 67–5, 114, 115, 67–116: Fig. 35a , 136, 137, and BUX 68–44: Fig. 35k , 123, 124, 125, 126, 135: Fig. 34c , 136, 137, BSK-A27, BW where it is straight and transverse. 56–59, CH 17, 22, 24; CSBX 47), the postmesoconid spur,

Te postprotocristid is strong, thick distally and which is more or less bulged or elongated obliquely. Te oblique mesiobuccal to distolingual; it is always longer mesoconid and postmesoconid are, in some cases, undisthan the prehypocristid. tinguishable (CSBX 47, 54; CH 24; BUX 67–116).

Te ectolophid area, defined from the distal end of the Te entolophid can be almost transverse or slightly postprotocristid to the mesial end of the prehypocris- curved distally. It usually joins the mesial end of the pretid, appears variable. Te Figure 36 illustrates this vari- hypocristid, together with the low distal ectolophid. It ation with schematized drawings of the buccal area of lowers at the level of this junction, sometimes interrupts. the m1–m2 from Bouxwiller. Te mesoconid can occupy On BUX 67–133, the entolophid is not continuous and most of the ectolophid (BUX 67–19, 111; BUX 68–33). formed only by small isolated oblique ridges. Te buccal On both sides of this mesoconid, the ectolophid is short. junction of the entolophid often occurs either more lin- Its mesial part is generally in the continuity of the post- gually, to the postmesoconid or the postmesoconid spur; protocristid, and hardly distinct. Its distal part is lower, or more distally, to the anterolingual wall of the hypocwhich interrupts on weakly worn or unworn teeth. How- one (BUX 67–130, 132; BUX 68–39; BW 56–59; CSBX ever, the path of this ectolophid + mesoconid varies. 54). Te entolophid usually bears an entoconulid, which Te postprotocristid is thick and frequently swollen at is however frequently worn and difficult to identify; it its end in a “premesoconid”-like structure (BUX 67–11, is only visible on BUX 67–5, 19, 25, BW 56–59, CH 24, 25, 141; BSK-A26, A28). Tis structure prolongs in a CSBX 40, 47, 56. One, rarely two, distomesial spur(s) or lingual spur of variable size (BUX 67–25, 110, 111, 112, ridge(s) frequently descend(s) from the entoconulid in 123, 130, 132, 136; CH 22, 24; CSBX 40, 41, 44, 46, 47, the central basin.

48), two lingual spurs (BUX 67–132, 140), or one buccal A few extra-ridges, wrinkles or granules are present in spur ( CH 13). On the m1 BW56-59, this spur is long at the central basin, but often erased by wear. Some of these the end of the postprotocristid but does not present any are organized in oblique ridges from the distal extremlingual swelling. It is indistinct or absent on the m2 BUX ity of the lingual metalophulid I, or/and from the lingual 67–116, 117, and 129. On worn teeth, the swelling or extremity of the buccal metalophulid I to the basin floor. the spur of the premesoconid are not visible (BSK-A27: Tere are two well-distinct oblique extra-ridges (BSK Fig. 36 , BSK-A29 BUX 67–23, 120, 139). Te short mesial A22, 24), one on BUX 67–19, 128, 137, CSBX 40, 47, 52, part of the ectolophid is higher than the distal one, and 56, and CH 22, three on BUX 67–114, 136, BUX 68–36, rarely distinct from the junction premesoconid–meso- 39, and BW 56–59. Te extra-ridges are numerous on conid. Te shape of the mesoconid varies with wear: BUX 67–114, 137, and BW 56–59; CSBX 52.

it can be bulbous, reduced or stretched. BUX 67–115 m 3. ( Fig. 37 ). Among the measured m3, three are much display a peculiar morphology, with bulbous cuspids, larger than the others are, and are described below as?P. conids (mesoconid, premesoconid at the extremity of the cf. alsaticus morphotype 1 and? P. cf. alsaticus morphopostprotocristid, postmesoconid spur, anteroconid, and type 3 ( Table 4B). If another teeth is much shorter (BUX

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Fig. 35 Lower m2 of? Protadelomys alsaticus Hartenberger, 1969 from Bouxwiller (Bas-Rhin). a BUX 67-116, right m2; a1, occlusal view; a2,buccal aspect; a3,lingual aspect. b BUX 67-132, left m2; b1, occlusal view; b2, buccal aspect; b3, lingual aspect. c: BUX 67-130, right m2; c1, occlusal view; c2, buccal aspect; c3, lingual aspect. d BUX 67-127, left m2; d1, occlusal view; d2, buccal aspect; d3, lingual aspect. e CSBX 49, right m2; e1, occlusal view; e2, buccal aspect; e3, lingual aspect. f BUX 67-112, right m2; f1, buccal aspect;f2, lingual aspect; f3, occlusal view. g CSBX 56,left m2; g1, occlusal view; g2, buccal aspect;g3, lingual aspect. h BUX 67-110, left m2; h1, occlusal view; h2, buccal aspect;h3, lingual aspect. i BUX 67-119, right m2; i1, buccal aspect; i2, lingual aspect; i3, occlusal view. j: BUX 67-141, right m2; j1, buccal aspect; j2, occlusal view; j3, lingual aspect. k: BUX 68-44, left m2; k1, occlusal view;k2, buccal aspect; k3, lingual aspect. l: BUX 67-33, left m2; l1, occlusal view; l2, buccal aspect; i3, lingual aspect. m: BUX 67-133, right m2; m1, occlusal view; m2, buccal aspect; m3, lingual aspect. n: BUX 67-140, left m2, occlusal view. Scale bar = 1 mm

67–155), its features seem to enter the whole variability. BUX 68–37, is here referred to? P. cf. alsaticus morphotype 2. It has a relatively short oblique postprotocristid, a low mesial ectolophid; the mesoconid is strong and prolonged in a thick postmesoconid. Te distal ectolophid is higher than the mesial one; the prehypocristid is thin and short. It differs from BUX 67–155 and from all the other specimens in the absence of a thick postprotocristid and of a premesoconid spur or ridge.

In all m3, the lingual metalophulid is mesial, except on BUX 67–160, where it is distally oriented. Te occurrence and strength of the ectomesolophid and of a more or less mesiodistal ridge from the lingual metalophulid are variable among all the m3. Te ectomesolophid is long on BSK-A25, BUX 67–151, 153, 159, 165, and 168. A mesostylid, more or less distinct from the postmetacristid, occurs on CSBX 45, BUX 67–14, 151, 152, 157, 159, 160, and 165. On BSK-A29 and BUX 67–168, the mesostylid prolongs buccally in a short lingual mesolophid, the metaconid appears more massive, thicker at its base, than on the other specimens.

We observed the same main variation along the postprotocristid–ectolophid area, but less pronounced than on m1–2. Te post-hypocristid is relatively short up to the hypoconulid area. Te hypoconulid is weakly bulged, single or often duplicated (e.g., BUX 68–37; 67–53, 151, 154, 155, 158, 164, 168). Te posterolophid is short, generally ending at the distal base of the entoconid.

Remarks and comparisons Even if? P. alsaticus has its postprotocristid thick, long and oblique with its distal end often swollen with a premesoconid spur, like in P. lugdunensis , morphological differences involving the lower teeth are observed, together with the differential development of extra-ridges and granules: in P. lugdunensis , the cusps are more bulged, the entolophid is more continuous, the postprotocristid is fused to the mesoconid area (no distinct pre, meso and postmesoconid elements).

Figures

Fig. 27 Bivariate graph of the size (width/length) of the upper (A) and lower (B) teeth of?Protadelomys alsaticus Hartenberger, 1969 from Bouxwiller (Bas-Rhin) (dp4/DP4 and p4/P4: red marks; upper and lower molars: black marks). From Bouxwiller, a few teeth are identified as?P. cf. alsaticus sp. indet 1 (purple marks), sp. indet 2 (turquoise blue marks) and sp. indet 3 (green marks). On B, four teeth (orange marks) are Masillamys parvus from Messel (Germany)

Fig. 28 Bivariate graph of the size (width/length) of the upper (A) and lower (B) teeth of?Protadelomys alsaticus Hartenberger, 1969 from Bouxwiller (Bas-Rhin) (black marks,PaB) compared to the size of the teeth of Protadelomys cartieri (Stehlin & Schaub, 1951), from Egerkingen (Swiss Jura) (red marks, PcE)

Fig. 31 Upper M2 of?Protadelomys alsaticus Hartenberger, 1969 from Bouxwiller (Bas-Rhin). a BUX67-2, left M2, Holotype; a1, occlusal view; a2, lingual aspect; a3, buccal aspect. b CH43, right M2; b1, occlusal view;b2, lingual aspect. c: CH41, left M2; c1, occlusal view, c2, lingual aspect; c3, buccal aspect. d CH32, left M2; d1, occlusal view; d2, lingual aspect. e BUX67-44, left M2; e1, occlusal view; e2, lingual aspect; e3, buccal aspect. f CSBX69, left M2; occlusal view. g CSBX33,right M2; occlusal view.h BUX67-6, right M2; occlusal view.i BUX67-56, left M2; i1, occlusal view; i2, lingual aspect; i3, buccal aspect. j: BUX67-72, left M2; j1, occlusal view; j2, lingual aspect; j3, buccal aspect. k: BUX67-52, left M2; k1, lingual aspect; k2, occlusal view; k3, buccal aspect. l: BUX67-79, left M2; occlusal view. Scale bar: 1 mm

Fig. 29 Upper DP4 and P4 of?Protadelomys alsaticus Hartenberger, 1969 from Bouxwiller (Bas-Rhin).a CSBX67-1 left DP4; a1, occlusal view; a2, lingual aspect; a3, buccal aspect. b CSBX4, left DP4; b1, occlusal view; b2, lingual aspect; b3, buccal aspect. c: CSBX1, left DP4; c1, buccal aspect; c2, lingual aspect; c3, occlusal view. d CSBX27, left DP4; d1, buccal aspect; d2, lingual aspect; occlusal view. e CSBX5 left P4; e1, occlusal view; e2: lingual aspect; e3, buccal aspect. f CSBX6,right P4; f1, occlusal view; f2, lingual aspect; f3, buccal aspect. g CSBX7, left P4; g1, occlusal view; g2, lingual aspect; g3, buccal aspect. h CH48, left DP4; h1, occlusal view; h2, buccal aspect; h3, lingual aspect. i CSBX9,right P4; i1, occlusal view; i2, buccal aspect; i3, lingual aspect. j: CSBX26, right P4; j1, occlusal view; j2, lingual aspect; j3, buccal aspect.: k: CSBX28,right P4; k1, occlusal view; k2, buccal aspect; k3, lingual aspect.l: CSBX29, right P4; l1, occlusal view., l2, lingual aspect.Scale bar: 1 mm

Fig. 30 Upper M1 of?Protadelomys alsaticus Hartenberger, 1969 from Bouxwiller (Bas-Rhin). a CSBX32,right M1; a1, occlusal view; a2, lingual aspect; a3, buccal aspect.b CSBX67,left M1; b1, occlusal view; b2, lingual aspect; b3, buccal aspect. c: CH41, right M1; c1, occlusal view, c2, buccal aspect; c3, lingual aspect. d BUX67-24, left M1, occlusal view. e BUX67-66, right M1, occlusal view. f BUX67-61, right M1; f1, occlusal view; f2, lingual aspect; f3, buccal aspect.g BUX67-68,left M1; g1, occlusal view; g2, lingual aspect;g3: buccal aspect.h BUX67-54, right M1; h1, occlusal view; h2, lingual aspect. i BUX67-47, left M1; i1, lingual aspect; i2, occlusal view; j: BUX67-53, right M1, weakly worn, occlusal view. k: BUX67-43,right M1; k1, occlusal view; k2, lingual aspect. l: CH49, left M1; l1, occlusal view; l2, lingual aspect. m: BUX67-46, right M1; m1, occlusal view; m2, lingual aspect; m3: buccal aspect. Scale bar: 1 mm

Fig. 2 Dental terminology (modified after Vianey-Liaud & Marivaux, 2021). A Upper molars: Al, name of flexi. 1, anteroflexus; 2, mesoflexus; 3, posteroflexus; 4, antesinus; 5, sinus; 6, posterosinus. Main cusps colored in grey,conules and styles, in light purple. A2, crest and cusps. 1, anteroloph; 2, anterostyle; 3, parastyle; 4, preparacrista; 5, paracone;6, postparacrista;7, protoloph (buccal+ lingual); 8, paraconule; 9, preparaconule; 10, preprotocrista; 11, protocone; 12, protocrista;13, postprotocrista; 14, endoloph; 15, prehypocrista; 16, hypocone; 17, post-hypocrista; 18, posterostyle; 19: posteroloph; 20:metastyle; 21, metacone; 22,buccal metalophule II; 23, buccal metalophule I; 24, metaconule; 25,three positions of the lingual metaloph; 26, premetacrista;27, mesostyle; 28,ectocingulum; 29, mesoloph (buccal); 30, postmetacrista. B Lower molars. B1: Main cuspids colored in grey, conulids and stylids, in light purple, Names of flexids: I, anteroflexid; II + III, mesoflexid;IV, posteroflexid.1, two positions of the anterolophulid; 2, anterocingulid; 3, antesinusid; 4, protoconid spur; 5, premesoconid spur, or ridge or swelling; 6: postmesoconid spur, or ridge or swelling; 7, entoconulid; 8, extra-ridges; 9, sinusid..B2, other crestids and cuspids. 1, anteroconid; 2, anterolophid; 3, premetacristid; 4, metaconid; 5, postmetacristid;6, mesolophid (lingual +buccal); 7, mesostylid; 8, entoconid; 9, entolophid (lingual + buccal); 10, posterolophid; 11, hypoconulid; 12, post-hypocristid; 14, hypoconid; 15, mesoconid;16, ectomesolophid; 17, ectocingulid,ectostylid;18, ectolophid; 19, postprotocristid;20, protoconid; 21, different paths of the buccal metalophulid:the most mesial and the medial one as buccal metalophulid I; 22, different paths of the lingual metalophulid I, and II for the most distal path; 23, path of the metalophulid II, with buccal part made with the postprotocristid.

Fig. 3 Bivariate graph of the size (width/length) of the upper (A) and lower (B) teeth of the rodent’s species from Egerkingen (Swiss Jura).The colored lines joins the different loci on a same jaw. A upper teeth. Protadelomys cartieri (Stehlin & Schaub,1951): Ef 1002, Holotype,P4 to M3, red line; Ek 245, M1 to M3, orange line; EK H006, P4 to M2, purple line; EK H005, M1 to M3, blue line; He 14, M1–M2, geen line; Eg 596, M1–M2, turquoise line. Homoetreposciurus egerkingensis nov. gen, nov. sp.: Ek 85, M1, black circle. B lower teeth. Protadelomys cartieri (Stehlin & Schaub, 1951): Ek H002, p4–m1, blue line;: Ek 250,p4–m2, yellow line; Ek 587, p4–m3, orange line; Ek 248, p4–m3, green line. Protadelomys lugdunensis Hartenberger, 1969: Em 21, p4 to m3. Homoetreposciurus egerkingensis nov. gen, nov. sp.: Ek H004,p4 to m3, purple line; Ek 79, dp4, purple circle. Eoelfomys nov. gen. nov. sp: Ek H003, p4 to m3, red line

Fig. 32 Upper M3 of?Protadelomys alsaticus Hartenberger, 1969 from Bouxwiller (Bas-Rhin). a BUX67-86, right M3; a1, occlusal view; a2, lingual aspect; a3,buccal aspect. b BUX67-16, left M3; b1, occlusal view; b2, lingual aspect. c: BUX67-85, left M3; c1, occlusal view, c2, lingual aspect; c3, mesial aspect. d BUX67-22, left M3; d1, occlusal view; d2, lingual aspect; d3, buccal aspect. e BUX67-84, right M3; e1, occlusal view; e2, lingual aspect; e3, buccal aspect. f BUX67-83, left M2; f1, occlusal view. f2, lingual aspect; f3, buccal aspect. Scale bar: 1 mm

Fig. 33 Lower dp4 and p4 of?Protadelomys alsaticus Hartenberger, 1969 from Bouxwiller (Bas-Rhin). a CSBX43,right dp4; a1, occlusal view; a2, buccal aspect; a3,lingual aspect. b CH55, left dp4; b1, occlusal view; b2, buccal aspect; b3, lingual aspect.c: BUX67-100, left dp4; c1, occlusal view; c2, buccal aspect;c3, lingual aspect.d BUX67-104, left dp4; d1, occlusal view; d2, buccal aspect; d3, lingual aspect. e BW56-55, left dp4; occlusal view. f CSBX50,left dp4; f1, occlusal view; f2, buccal aspect; f3, lingual aspect. g CH26, left p4; g1, occlusal view; g2, buccal aspect;g3, lingual aspect. h BW56-57, left p4; h1, occlusal view; h2, lingual aspect. i BUX67-101, left p4; i1, occlusal view; i2, buccal aspect;i3, lingual aspect.j: BUX67-102, left p4; j1, occlusal view; j2, buccal aspect;j3, lingual aspect. k: BUX67-103, left p4; k1, occlusal view; k2, buccal aspect; k3, lingual aspect. l: BUX67-107, right p4; l1, occlusal view; l2, buccal aspect; l3, lingual aspect. m: BUX67-105, left p4; m1, occlusal view; m2, buccal aspect; m3, lingual aspect.Scale bar=1 mm

Fig. 34 (See legend on previous page.)

Fig. 35 (See legend on previous page.)

Fig. 36 (See legend on previous page.)

Fig. 37 Lower m3 of?Protadelomys alsaticus Hartenberger, 1969 from Bouxwiller (Bas-Rhin). a BUX67-14, right m3; a1, occlusal view; a2, buccal aspect; a3,lingual aspect. b BUX67-153, left m3; b1, occlusal view; b2, buccal aspect. c: BUX67-164,left m3; c1, occlusal view; c2, buccal aspect. d BUX67-157, left m3, occlusal view. e BUX67-158, right m3; occlusal view. f BUX67-155, left m3; occlusal view. g BUX67-160, left m3; occlusal view. h BUX67-159, left m3; occlusal view. i BUX67-29, left m3; occlusal view. j: BUX67-151, left m3; occlusal view. k: BUX67-152, left m3; occlusal view. l: BUX67-168, left m3;, occlusal view. Scale bar =1 mm