Tapirus priscus Kaup, 1833
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publication ID |
https://doi.org/10.1186/s13358-024-00342-5 |
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persistent identifier |
https://treatment.plazi.org/id/03C187E5-3A21-FFC2-A348-FC5FFC2A166F |
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treatment provided by |
Felipe |
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scientific name |
Tapirus priscus Kaup, 1833 |
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Figures 4 View Fig and 5 View Fig
Referred material: IPS11264, left maxillary fragment with DP2–M1 from CLL1 ( Golpe-Posse & Crusafont-Pairó, 1982: Fig. 1 View Fig ); IPS11265, left M2 from CLL1 (figured as an M1 by Golpe-Posse & Crusafont-Pairó, 1982: fig. 2); IPS11266, partial right lower molar, probably m1 (reported, but not figured, as an m1? or dp4? by Golpe-Posse & Crusafont-Pairó, 1982); IPS11335, worn-out right DP2 from CLL1 (reported but not figured by Golpe-Posse & Crusafont-Pairó, 1982); IPS70116, right DP4 from CCL 1W. S; IPS28172, worn-out lower right molar, probably m2 (identified as a left m1 of the suid Listriodon splendens with old catalog number [IPS1061] by Golpe-Posse, 1971, 1972); IPS136651, right mandibular fragment with m2–m3 from CCN20 (m3 is detached from the mandible); IPS133767, partial skull from CGS-I5 preserving the maxillary and premaxillary bones and bearing DI1, DI2, DP1, DP2, DP4 and M1 on the right side, and DI1, DI2, DI3, DP3–M1 on the left. See measurements in Table 1.
Description: Te partial skull IPS133767 ( Fig. 4 View Fig ) preserves the maxillary and premaxillary bones and bears the right DP1–DP2, DP4, and M1 and the left DP3–M1
( Fig. 4a View Fig ), indicating that it belongs to a juvenile individual. Te premaxillary bone is not connected with the main cranial fragment ( Fig. 4b–c View Fig ), the two parts being separated along the premaxillary-maxillary suture, which in lateral view terminates just in front of the canine alveolus ( Fig. 4b–c View Fig ). Te premaxilla bears the left DI1– DI3 and the right DI1–DI2, although the alveolus of the right DI3 is also present. Contrary to permanent incisors, DI1 and DI2 are longer than wide on extant Tapirus species, and display a less developed lingual cusp, similarly to IPS133767. DI3 is smaller than I3 and proportionally similar to DI2, while I3 is normally big and caniniform. In turn, the maxillary bone bears the alveoli of the right and left deciduous canines. Te postcanine diastema is ~ 40 mm in length, and the most posterior part of the premaxilla terminates anteriorly to the DP1 ( Fig. 4b–c View Fig ). Te DI1 bears a lingual cusp, and its occlusal surface is labiolingually concave. Te DI2 is more asymmetric than the DI1 and displays a lingual cingulum. Both deciduous incisors display a triangular occlusal contour that is wider labially than lingually. Te DI3 is slightly caniniform and displays a labial sulcus. Te DI2 is larger than the DI1 and DI3. Te DP1 bears a distal cingulum and an elongated lingual cusp not connected with the ectoloph
( Fig. 5a View Fig ). Te DP2 ( Fig. 5b View Fig ) shows a labial cingulum below the metacone, and distal and mesial cingula. On this tooth, the parastyle is developed and connected to the protoloph by a short ridge. Te protoloph is oblique and connected with the ectoloph anteriorly to the paracone, while the metaloph is transverse and connected with the metacone just at mid-height of the latter cusp. Te protocone is less developed than the hypocone, and a lingual cusp is present at the entrance of the median valley. Te DP3, DP4, and M1 bear a large parastyle, well-separated from the paracone. On the DP3 ( Fig. 5e View Fig ), the paracone is larger than the metacone, unlike in the DP4 ( Fig. 5g –h View Fig ) and M1 ( Fig. 5k View Fig ). Te protocone and hypocone are similar in size in the DP3 and DP4, but the protocone is larger in the M1. Mesial, distal, and labial (below the metacone) cingula are present on the DP3, DP4, and M1. A small lingual cusp is present on the DP3 at the entrance of the median valley. Te metaloph is shorter than the protoloph on all these teeth. On the DP3 and DP4, the metaloph is taller than the protoloph, and the hypocone is taller than the protocone, while on the M1 the two latter lingual cusps are similar in height. In labial view, the paracone is similar in height to the metacone on the DP2 and DP3, but taller than the metacone on the DP4 and M1.
All the teeth in the maxillary fragment IPS11264
( Fig. 4g –i View Fig ), which preserves the DP2–M1 series, bear a continuous mesial cingulum. Te labial cingulum is present below the metacone and is connected with the distal cingulum ( Fig. 4i View Fig ). A faint lingual pillar is present on the DP2 ( Fig. 5c View Fig ) at the entrance of the median valley. On the DP4 ( Fig. 5i View Fig ) and M1 ( Fig. 5l View Fig ), the distal cingulum turns toward the apex of the hypocone, while it is low on the DP2 ( Fig. 5c View Fig ) and DP3 ( Fig. 5f View Fig ). Te protocone and hypocone are well separated and the median valley is wide on all the teeth ( Fig. 4g View Fig ). Te DP3–M1 have a fully developed protoloph and metaloph, joined with the ectoloph in front of the paracone and the metacone respectively ( Fig. 5f, i, l View Fig ). On the DP2 ( Fig. 5c View Fig ), the protoloph is more obliquely oriented than the metaloph, while it is transverse on the other teeth; the metaloph is weakly connected with the ectoloph. Te parastyle is present and distinguished from the paracone, but on DP2– DP4 it is smaller than on the M1 and separated from the paracone by a deeper groove. Te hypocone is slightly taller than the protocone on all the teeth. Te paracone is taller than the metacone on DP3–M1 but not on DP2. Te labial occlusal contour of the DP2 is markedly concave; this feature is less marked on the other teeth and basically absent from the M1 ( Fig. 5l View Fig ), where the minimal width of the crown almost equals its posterior width.
In the worn-out DP2 IPS11335 ( Fig. 5d View Fig ), most of the characters described above cannot be observed due to the advanced wear. Te tooth displays a subtrapezoidal occlusal contour, concave on the labial side. Te tooth preserves part of the mesial cingulum and a distolabial cingulum. Te parastyle appears well separated from the paracone by a deep groove. Te protoloph is oblique and the metaloph is straight but weakly connected with the ectoloph. In labial view, the paracone and metacone are separated and look similar in height.
Te DP4 IPS70116 is a right DP4 ( Fig. 5j View Fig ), published as M1 by Golpe-Posse and Crusafont-Pairó (1982). Similarly to the other DP4s described previously, the tooth, in occlusal view, has a slightly concave labial side and a strongly concave lingual side. Te minimal width in the middle of the tooth is smaller than the posterior width. Tese characters suggest the tooth is deciduous. Te parastyle is large and separated from the paracone by a deep groove. Te mesial cingulum is continuous, and the labial-distal cingulum is strong. A large cusp is present at the entrance of the median valley, below the hypocone. Protoloph and metaloph are continuous and joined with the ectoloph. Between the paracone and the parastyle, on the labial side, there is an additional small cusp similar to DP4 IPS133767. Te hypocone is slightly taller than the protocone.
Te M2 IPS11265 ( Fig. 5m View Fig ) bears a mesial and distal cingula, as well as a labial cingulum below the metacone. In labial view, the metacone and paracone are similar in height, while in lingual view the protocone is slightly taller than the hypocone. Te parastyle is large and well separated from the paracone. Te protoloph and the metaloph are high and connected with the paracone and the metacone, respectively.
Te partial lower molar (probably m1) IPS11266
( Fig. 5n View Fig ) displays a distal cingulum. Te protolophid and metalophid are separated, and the protolophid is taller than the metalophid in labial view.
In the m2–m3 of the mandibular fragment IPS136651
( Figs. 4d–f View Fig , 5p View Fig ), the labial cingulid is absent. In labial view, the protoconid is taller than the hypoconid. Te metalophid is not well developed and does not reach the protolophid. A metastylid is present and the hypoconulid is reduced to a cingulum ( Fig. 5p–q View Fig ).
In the worn-out lower molar (probably m2) IPS28172
( Fig. 5o View Fig ), the protolophid is wider than the metalophid, the distal cingulid is still visible, and a mesial cingulid is barely visible on the mesiolabial corner of the crown. No further features can be discerned.
Comparisons
Comparisons among the studied material and with the tapirid from Teuleria del Firal
Te isolated DP2 IPS11335 ( Fig. 5d View Fig ) resembles those of IPS133767 ( Fig. 5b View Fig ) and IPS11264 ( Fig. 5c View Fig ) in the general subtrapezoidal occlusal contour of the crown and the strong labiolingual constriction between the mesial and distal cusps. On all the described DP2s, the protoloph bends distolingually and is curved at the level of the connection with the paracone. Te parastyle is well developed and barely connected with the mesiolabial side of the protoloph (not clearly visible on IPS11264 because of damage). On the described DP2s, the labial cingulum is strong, continuous below the metacone, and connected with the distal cingulum. Te latter terminates close to the mid-lingual side of the hypocone. Te entrance of the median valley bears a large cusp on IPS133767 and a faint pillar on IPS11264. Additional enamel folds develop from the protocone and the hypocone toward the median valley on all these teeth; the metaloph is barely connected with the ectoloph, and the hypocone is larger than the protocone. On the DP2s of IPS11264 and IPS133767, an enamel fold on the ectoloph, mesially to the metacone, is also present. On the IPS11264 DP2, the mesial cingulum is slightly stronger than on that of IPS11264 and the median valley looks narrower on its inner portion. Dimensionally, the DP2 of IPS11264 and IPS11335 are very similar in size and proportion, while that of IPS133767 is somewhat narrower in Wm. Similar metrical differences can be detected between the DP3s of IPS133767 and IPS11264 ( Table S1). However, this dimension is also slightly variable in the comparative samples of Tapirus indicus (Wm varies from 20.5 mm to 18.68 mm on the DP2) and Tapirus terrestris , even within a single individual. In terms of occlusal shape, the DP3s of IPS133767 and IPS11264 are similar regarding the development of cusps and cingula. Only the labial cingulum looks somewhat stronger on IPS133767. Te DP4s of IPS133767 and IPS11264 are morphologically identical, but those of IPS133767 are a little bit smaller. Te length of DP2–DP 4 in IPS133767 (60.5 mm) is like that in IPS11264 (63.0 mm). Te M1 of IPS133767
( Fig. 5k View Fig ) differs from that of IPS11264 ( Fig. 5l View Fig ) in the possession of an additional fold within the postfossette, additional enamel folding on the median valley and the mesial side of the metaloph, and a slightly smaller size. However, these differences fall within the intraspecific variability of T. indicus . Te metrical differences between the two described M1s are smaller than those reported for this tooth locus in Ta. pannonicus from Dorn-Dürkneim and T. arvernensis from Camp dels Ninots ( Table S1), and those displayed by T. terrestris and T. indicus . Te m2 IPS28172 and that of IPS136651 are very similar in size, but the advanced stage of wear of the former precludes an exhaustive comparison. All the lower molars (except IPS28172) have the metalophid separated from the protolophid, a protoconid taller than the hypoconid, a strong metastylid, and a strong distal cingulid.
Te material from Teuleria del Firal was previously identified as a P2 or P3 and a fragment of M1 ( Chevalier, 1909; Bataller, 1918, 1924: pl. 2, figs. 7, 8; Golpe-Posse & Crusafont-Pairó, 1982). However, the upper premolar figured by Bataller (1924: pl. 2, fig. 7) is actually a DP2, morphologically comparable with that of IPS133767. Te length and posterior width of the DP2 from Teuleria del Firal (estimated from the Bataller’s figure) are 21.6 and 19.6 mm, respectively, thus falling within the DP2 variability from the Vallès-Penedès specimens ( Table S1). Te length of the partial M1 from Teuleria del Firal ( Bataller, 1924: pl. 2, fig. 8) was reported as 28 mm by Bataller (1924: p. 11), which exceeds the M1 lengths for all Late Miocene and Pliocene tapirid species from Europe. In fact, this tooth does not fit well with the morphology of a tapir upper molar and thus possibly represents a deciduous premolar of a rhinocerotid. Based on the comparisons above, all the studied specimens, as well as the DP2 from Teuleria del Firal, can be assigned to the same species.
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