Adcrocuta eximia (ROTH et WAGNER, 1854)

Adcrocuta eximia (ROTH et WAGNER, 1854)

Text-figs 8, 9

M a t e r i a l. Thermopigi: Skull with P2–M1 left SIT 1421; 2P2 right SIT 531 and left 940, P3 left SIT 1057, mandible with p2–m1 fr. left SIT 713+714; m1 right SIT 529, anterior pad, d4 fr right SIT 1280, p3 right SIT 530; coprolite SIT 1359.

Platania: A maxilla with the right and left P2–P4, PLD 464.

D e s c r i p t i o n. Thermopigi: The corroded skull SIT 1421 bears the very poorly preserved left tooth row P2–P4 and M1, nasals, nasal cavity, infra-orbital foramina, frontal with the orbital cavities and ecto-orbitals, post-orbital constriction to the parietals, most of the left zygomatic arch, and a palate showing a deep depression below the metastyle of the left P4, in front of the molar, followed by the choanae ( Text-fig. 8a 1–3). The toothrow is damaged ( Text-fig. 8a 4); only traces remain that allow us to make a few measurements ( Tab. 4). There are traces of the mesial accessory cusp of the P2 and P3, and the metastyle of the upper carnassial. The worn and slender M1 rotates 90 degrees inwards; paracone, metacone and protocone are barely distinguishable. There is palatal asymmetry, on the right side of the maxilla, where paleopathological evidence indicates a type of exostosis bearing the roots of P2 and P3 .

Of the two isolated P2s, SIT 940 retains only the upper part of the unworn crown, the pointed tip and the two well-defined crests ( Text-fig. 8e). The preserved dimensions are: length 12 mm, breadth 8 mm. The P2 SIT 531 is almost complete and only a little worn ( Text-fig. 8d). Two sharp anterior and posterior crests extend from the tip of the tooth, the latter meeting the well-distinct posterior accessory cusp ( Tab. 4). The P3 SIT 1057 is almost complete, missing only the mesial part with the accessory cusp ( Text-fig. 8c). The main cusp is unworn and strong with two sharp crests extending from the tip anterior and posterior of the tooth. The latter terminates in the well-developed posterior accessory cusp; dimensions in Tab. 4.

The left mandible SIT 713+714 preserves the corpus with p2-m1 ( Text-fig. 8b 1–3). The slightly worn tooth row consists of the complete p2, p3, the talonid of the damaged p4, and the mesial half of the lower carnassial. The alveolus of the single root p1 is also preserved (Depth = 4.45 mm), as well as parts of the symphysis. The corpus is relatively high and straight at its preserved inferior border. There are two mental foramina below p2: the larger below the middle and the smaller below the posterior border of the tooth. The p2 is short but robust, with a small anterior and a larger posterior accessory cuspid. There is a lingual cingulum. The larger p3 bears a strong anterior and a posterior accessory cuspids on the mesio- and distolingual sides of the tooth. There is a faint buccal cingulum. The p4 is damaged, and only the well-developed distal accessory cuspid is preserved on a large, raised base of the distal cingulum around the distal area of the tooth. The mesial part of the lower carnassial is preserved with a mesial cingulum at the crown base, whereas only the root of the distal part of the tooth remains. Dimensions of the mandible and teeth are in Table 4.

From the lower deciduous carnassial d4 SIT 1280, only part of the blade is preserved ( Text-fig. 8h). It is slightly worn. The paraconid and protoconid form an angle of 115° at 13 mm between their peaks. The preserved dimensions are a length of 15.73 mm and breadth of 6.0 mm. The nearcomplete p3 SIT 530 is well-preserved and unworn. The protoconid is relatively high and the distal crest is sharp. The mesiolingual accessory cuspid is weak, while the distolingual one is larger ( Text-fig. 8f). Dimensions are in Tab. 4. From the carnassial SIT 529, a half-fragment bears the unworn paraconid of a juvenile. The mesiolingual crest is strong. The preserved dimensions are a length of 13.10 mm and breadth of 10.05 mm ( Text-fig. 8g).

The well-preserved coprolite SIT 1359 shows a typical constriction at one third of its total length and a shallow depression at one of its ends ( Text-fig. 8i). Dimensions are length 47.31 mm, breadth 37.08 mm and height 24.49 mm.

Platania: Maxilla PLD 464 preserves both right and left tooth rows with P2–P4, nasal cavity and the left infraorbital foramen (ca. 6.5 mm) above and medial to the P3 roots ( Text-fig. 9a–c). Both tooth rows are well-preserved; only the protocone of the right carnassial is missing. The highcrowned tooth rows are slightly worn and with lingual cingula. P2 is oval shaped with a palatal cingulum, with sharp anterior and posterior crests, a vestigial anterior and a small posterior accessory cusp. P3 is large, with sharp mesiopalatal and distal crests, a small anterior and a larger posterior accessory cusp. The anterior part of the tooth is broader than the posterior. The upper carnassial is large, long, and robust. The parastyle is well-developed, the paracone high and the metastyle forms a long blade. The protocone is relatively weak, confined to the base of the tooth, posteriorly to the anterior border of the parastyle, typical for Adcrocuta (dimensions in Tab. 4).

D i s c u s s i o n. The PLD maxilla is described and discussed here to compare the two richest Turolian mammal sites, located close to each other in eastern Macedonia: Thermopigi and Platania. Thermopigi Adcrocuta (SIT) appears less robust than Platania (PLD) hyena. They generally fall within the variation between Axios Vallesian and Axios Turolian ( Text-figs 10, 11). When comparing SIT and PLD maxillae, it should be noted that (a) longer tooth row (even damaged) P2–P4 and carnassials in SIT than in PLD, (b) index B/LX100 for P2: SIT = 56.16, PLD= 71.10, (c) P3 higher but slenderer in SIT than in PLD and the B/ HX100 index: SIT=71.35, PLD=84.53.

The morphology of the Platania P2–3 (relatively narrow, with a strong mesial additional cusp and a strong lingual cingulum) indicates an earlier geological age of the Adcrocuta from Platania, and places it apparently in the pre-middle Turolian stage of premolar evolution of this hyena, close to some other Balkan samples from the Vallesian/Turolian boundary ( Spassov et al. 2018, 2019). This morphology seems to support the above-assumed biochronological position of the locality. Also, it is noteworthy to compare these two faunal associations of Thermopigi and Platania with Adcrocuta , as already discussed in earlier publications on rhinoceroses ( Tsoukala 2018), proboscideans ( Konidaris and Tsoukala 2020), bovids ( Vasileiadis et al. 2019), turtles ( Vlachos and Tsoukala 2014) and the paleoenvironment. The bite marks of Adcrocuta appear comparatively more often in the bone-remains of Platania than in those of Thermopigi. Especially in hipparions, young rhinos and bovids, there is a common presence of bitten and broken bones, presumably making it a feeding site for this top carnivorous scavenger.

Adcrocuta eximia upper teeth compared Adcrocuta eximia lower teeth compared

In Greece, Adcrocuta eximia is widespread and known from at least 20 sites dating from the late Vallesian to the late Turolian ( Koufos 2022b). The dental dimensions are close to those of Adcrocuta eximia from sites of Northern Greece, such as Axios Valley (late Vallesian, MN 10), Nikiti (early Turolian, MN 11) ( Koufos 2000, 2012, 2016) and Kryopigi Kassandra (MN 12/MN 13) ( Lazaridis 2015). It must be noted that the upper carnassials are more robust in the SIT and PLD specimens than those of the other sites ( Text-figs 10, 11).