Chalicotherium goldfussi, KAUP, 1833

Anquetin, Jérémy, Antoine, Pierre-Olivier & Tassy, Pascal, 2007, Middle Miocene Chalicotheriinae (Mammalia, Perissodactyla) from France, with a discussion on chalicotheriine phylogeny, Zoological Journal of the Linnean Society 151 (3), pp. 577-608 : 588-589

CHALICOTHERIUM GOLDFUSSI KAUP, 1833 A

Macrotherium giganteum Pictet, 1844

Diagnosis: In the present paper, C. goldfussi is not diagnosed by any autapomorphy. This is the consequence of our choice not to include the specimen CCECM Lgr 1065 from La Grive Saint-Alban within C. goldfussi for the time being, despite both anatomical evidence and the result of our cladistic analysis (see below).

Chalicotherium goldfussi displays the two synapomorphies of Chalicotherium , and almost all plesiomorphic characters mentioned in the diagnosis of the latter (except those of the skull, as no skull is known for this species). Both C. goldfussi and CCECM Lgr 1065 have a complete protoloph on P 3 [unambiguous synapomorphy of the clade ( C. goldfussi, CCECM Lgr 1065 )].

Lectotype: Right M 3 (HLM Din. 3167) described and illustrated by Kaup (1833a). This lectotype was designated by Schaefer & Zapfe (1971), who reviewed and illustrated the specimen.

Paralectotype: Right lower molar described by Kaup (1833a) as an M 3 ( HLM unknown number) .

Type locality: Eppelsheim (Rheinhessen, Germany).

Age: Late Miocene (Vallesian) , Deinotherium sands (MN 9).

Remains from Saint-Gaudens

De Bonis et al. (1995) described chalicothere remains from Saint-Gaudens (Haute-Garonne, France) in the MHNT collection: a left maxilla and a right M 3. These remains come from the Valentine Quarry, which is attributed to the late Middle Miocene MN 8 biozone ( Antoine, Duranthon & Tassy, 1997). Since then, one of us (POA) found a right hemimandible and a complete symphysis in the MHNT Valentine collection, both undescribed. In fact, this chalicothere from Saint- Gaudens was mentioned (without description or illustration) by Harlé (1898: 382) consisting of two half-jaws (‘demi-mâchoires’). These remains correspond to the maxilla described by de Bonis et al. (1995) and the hemimandible described herein. There is also an unnumbered M 1. These five specimens belong to the same individual although they bear different catalogue numbers.

The maxilla and the M 3 are numbered MHNT VAL- 1 and MHNT VAL-2, respectively [both unnumbered when de Bonis et al. (1995) described them], whereas the hemimandible and the symphysis are MHNT VAL-3 and MHNT VAL-4, respectively. Chalicothere remains from Saint-Gaudens are important because they can be confidently assigned to C. goldfussi (sensu this study) and include the first mandibular symphysis known for this species.

Right hemimandible MHNT VAL-3

The section anterior to the distal root of P 4 is missing, but the rest of the mandible is complete ( Fig. 5D ). The three molars are preserved. The corpus increases in height posteriorly. In transverse section, the inferior margin of the corpus is slightly swollen on its labial face. The ventral border of the corpus is straight and there is no ventral expansion of the angular area. There is a large retromolar space. The anterior border of the ramus is nearly perpendicular to the ventral border of the corpus. The ramus is elongated anteroposteriorly. The foramen mandibulare opens slightly ventral to the tooth row, beneath the coronoid process. The latter is flattened and curved posteriorly, and displays a strong mesiolabial crest. The area between the coronoid process and the condyle is more strongly concave in a vertical plane than in UT DKO 234, and is similar to the state in Moropus (Schizotheriinae) . The condyle is flat. Ventral and lingual to it, there is an oval articular surface for the postglenoid process. Just below, a small tubercle is present.

The molars ( Fig. 5E ) bear a talonid longer than the trigonid. In occlusal view the former is V-shaped, whereas the latter is U-shaped. The paraconid is low, but well defined and underlined by the mesial cingulum. The ‘metastylid’ is strong and distinct from the metaconid: consequently, the hypolophid does not reach the metaconid summit, even on worn molars. The metacristid is strong. The cingulum is absent lingually and enlarged distally. There are well-developed vertical medial incisures on the distal walls of the metalophid and entolophid, and on the mesial wall of the hypolophid ( Fig. 5F ). Although these structures have not been described before, they can also be observed on remains from Sansan and on the specimen from La Grive Saint-Alban (CCECM Lgr 1065).

Symphysis MHNT VAL-4

The complete symphysis MHNT VAL-4 includes the beginning of the two corpuses ( Fig. 5C ). Only the right canine is preserved, but other teeth are represented by their alveoli. There are three incisors on each side ( Fig. 5B ). Alveolus size increases from I 1 to I 3. The canine is just behind the third incisor, and its lateral outline is triangular with a subvertical mesial face. There is a vertical crest running from the summit to the distolingual border of the tooth, which defines a large lingual groove.

In dorsal view ( Fig. 5C ) the incisor border is slightly convex anteriorly. Posterior to the canine, the symphysis constricts before broadening suddenly at the level of the corpuses. Unfortunately, there is no trace of the P 2 alveolus, so it is impossible to determine the posterior extent of the symphysis. Yet, the diastema between the canine and P 2 was long. The dorsal surface of the symphysis is concave.

In lateral view ( Fig. 5A ), the symphysis is very slender anteriorly and reaches the minimum thickness necessary for incisor insertion. The foramen mentale opens just posterior to the symphysis constriction.

In frontal view ( Fig. 5B ) the arrangement of canines and incisors is arched ventrally. The canine is anterodorsally implanted. The incisor border forms a plateau and the incisors are implanted strictly forward (as in Moropus ). The ventral face of the symphysis is smooth and no tuberosity is present.

Comparison with remains from the Late Miocene Deinotherium sands , Germany

Additional remains from Eppelsheim (type locality of C. goldfussi ) include a right maxilla (HLM Din. 3168) with P 2 –M 3 ( Zapfe, 1979: fig. 7). Zapfe (1989) also reported the presence of C. goldfussi at Höwenegg (Hegau, Germany), represented by a left M 2 (LNK te pli 3) and by a right P 4 (LNK te pli 2), M 1, and M 3 (LNK te pli 1). Comparison between these remains and those from Saint-Gaudens supports assignment of the latter to C. goldfussi .

A left mandible with M 1 –M 3 found in the Late Miocene (MN 12–13) of Henndorf (HMS unknown number), Austria, was also assigned to this species ( Schaefer & Zapfe, 1971: fig. 3a, b; Zapfe, 1979: fig. 40). However, several features, i.e. the absence of retromolar space, a symphysis extending posterior to the mesial part of P 4, a short diastema, and a V-shaped trigonid on the molars, contradict this assignment. These characteristics correspond to that of Anisodon . The Henndorf mandible, assigned to C. goldfussi since its first description, is the specimen that prevented authors recognizing the existence of two different chalicotheriine lineages. The mandible from Titov Veles ( Garevski & Zapfe, 1983) and those of Chalicotherium wuduensis Xue & Coombs (1985) from China were referred to Chalicotherium because they resemble the mandible from Henndorf. Now, with the description of new remains of C. goldfussi from Saint- Gaudens, we can confidently exclude the Henndorf mandible from this genus.

Figures

Figure 5. Chalicotherium goldfussi. Specimen from Saint- Gaudens (Valentine Quarry). Symphysis MHNT VAL-4: A, right lateral view; B, frontal view, note the three alveoli per side for the incisors (right alveoli are indicated); C, dorsal view. Right hemimandible MHNT VAL-3 with M1–M3 (same individual as MHNT VAL-4): D, labial view; E, occlusal view of the tooth row; F, distolabial view of M3 and M2 illustrating the presence of the medial incisures (see text). Scale bars: 1 cm.