Ursus arctos taubachensis Rode, 1935

Marciszak, Adrian, Kot, Małgorzata, Zarzecka-Szubińska, Katarzyna & Lipecki, Grzegorz, 2025, Ursidae (Carnivora, Mammalia) from Tunel Wielki Cave (southern Poland), Comptes Rendus Palevol 24 (14), pp. 241-302 : 262-263

Ursus arctos taubachensis Rode, 1935

( Fig. 16)

REFERRED MATERIAL. — Among 954 ursid remains from TW, five specimens were determined as belonging to U. arctos : a single fragment of the right maxilla with a strongly worn M1 and mesial part of the zygomatic arch ( MF/7547 , layer K1); one left C1 ( MF/7560 , layer M2); one crown of the left M2 ( TW 825 , layer K1); one left, slightly damaged talus ( MF/7515 , layer O); and one right, slightly damaged talus ( MF/7517 , layer O) .

EMENDED DIAGNOSIS. — About the size of Ursus arctos middendorffi or larger; flat and elongated forehead; large and massive incisors and canines; P1-P3 present; broad and large P4 often with additional cusplets, expanded paracone and enlarged protocone; p1 and p3 usually present; broader and more quadratic in occlusal view M1 with larger paracone and metacone, strong lingual cingulum collared maximally from mesial wall of the protocone to the distal wall of the hypocone and large surface of the inner talon field filed with grooves, lines and additional small cusplets; large and wide M2 with particularly broad and expanded trigon and broad and elongated talon, high and large paracone with strong developed grooves and ridges on their lingual wall, present metastyle and posthypocone, moderately developed distal cingulum, large surface of the inner talon field filed with grooves, lines and additional small cusplets and lingual cingulum reaches maximally after the hypocone; large and robust m1 with blunt mesial margin, double or triple metastylid, double or triple entoconid with their size decreasing significantly mesially, moderately to strong developed enthypoconid; robust m2 with the talonid wider than the trigonid, inner surface of trigonid with moderately to strong developed grooves and ridges, simple metastylid complex, moderately to strong developed enthypoconid; particularly large and broad m3 with mesolophid runs lingually and parallel to the metalophid, single enthypoconid, enthypoconid-hypoconid connection of the centrolophid, entoconid developed in the form of a serie of additional cusps on the lingual edge divided by transverse grooves, inner surface of talonid with moderately to strong developed grooves and ridges; massive metapodials with particularly robust shafts and distal epiphyses ( Rode 1935; Baryshnikov 2007).

DESCRIPTION

The complete C1 (MF/7560) metrically (L – 22.74 mm, B – 16.56 mm) falls into the size variability of males and females of U. deningeri , therefore it is impossible to recognise the species based on the measurements alone. On average, canines of spelaeoid bears are more robust, and size ranges of bears from arctoid and spelaeoid lineages actually overlap, if we take into consideration U. a. taubachensis ( Marciszak et al. 2019b). In addition, this is regardless of whether we compare not-sexed groups or take into consideration temporarily and sexed populations. Because of the great sexual dimorphism, when comparing different populations from different time periods, the best way is to compare males and females separately. Pleistocene and especially Holocene inidividuals of U. arctos are smaller than spelaeoid bears. However, among them there are many large individuals matched or even exceed the size of large individuals of U. deningeri . In the case of the canine from TW, it is rather of moderate size, comparable with those in adult males of extant U. arctos from Central Europe. The assignation as male canine is confirmed also by a thickened root, the bulging state of which, however, is far away from the massive roots of U. deningeri . The tooth is relatively short compared to more elongated and narrower crown in spelaeoid bears; this argument also supports the assignation of the specimen to this species.

The single M2 (TW 825) is a large and broad tooth (1 – 45.56 mm, 2 – 15.74 mm, 3 – 12.79 mm, 4 – 24.56 mm, and 5 – 22.45 mm). Its morphology corresponds well to the size and shape of the M2 of U. a. taubachensis ( Fig. 16). An elongated and rectangular M2 has expanded and broad trigon, and elongated and rather wide talon, narrowing gently distally. The rounded and moderately high paracone is placed far from the metacone and separated from it by a shallow and wide valley. Its mesial ridge is in contact with the mesial ridge of the protocone and is characterised by the development of an additional side branch running on the mesio-lingual slope of the parastyle, but not reaching the base of this cusp. In addition, the mesial ridge of the parastyle formed a group of 4-5 cusplets like structures that collared the mesial wall of the trigon (B2). The mesostyle complex is formed by the distal slope of the paracone and the mesial slope of the metacone (B2). The distal arm of the paracone is strongly curved cerntrally, that it lost connection with the mesial arm of the metacone and forms a separate arch. A few pillars, running from the base of the cusp and maximally reaching the half of its height, are situated on the internal wall of the paracone. In the metaloph complex, the metacone and the protocone are not directly connected, a few small cusplets occur between them, and the distally situated hypocone is developed in a double branch (B3). The posteroloph is developed as S-shaped, curved line, formed by a few low and small cusplets running between the metastyle and the hypocone. The entire talon field is covered by numerous small cusplets, which form two regular grooves (B/C). The talon field is collared by a thick wall of the distal cingulum, which forms numerous small cusplets (B). The metastyle and posthypocone are present but weakly developed as small and low cusps. A few pillars reaching the half of the height of the internal wall of the protocone are running from the base of this cusp. The lingual cingulum shows a relatively high evolutionary stage, running through the base of the protocone and terminating between the hypocone and the posthypocone.

Both tali are almost completely preserved, only in the distal-medial part a small piece of the bone is missing, which approximately corresponds to the distal process ( Fig. 16). A significant feature distinguishing arctoid and spelaeoid bears is the development of the sulcus tendinis musculi flexoris hallucis longi ( Rabeder et al. 2010). In both tali, this measurement cannot be made out quite accurately because of partial damage. In U. deningeri , this sulcus is almost twice as wide as in U. a. arctos ( Rabeder et al. 2010) . In the TW specimens, the sulcus seems to have a similar dimension as in U. a. arctos , but due to the fracture face on the medial edge, this cannot be said with sufficient certainty. The lateral edges of the trochlea run almost parallel, as in U. a. arctos . In U. deningeri , the medial edge runs sloping from mediodistally to lateral-distally and forms a steep angle with the expansion of the lateral edge ( Fig. 16). The inclination of the medial edge of the trochlea is connected to the sprain of the distal epiphysis of the tibia ( Mottl 1940; Rabeder et al. 2010). The specimens considered are also smaller than those of U. deningeri (MF/7515: 1 – 49.74 mm, 2 – 42.24 mm; MF/7517: 1 – [est. 49.50 mm], 2 – 43.09 mm.

COMPARISON AND REMARKS

The material of Ursus arctos from TW is represented only by five specimens, but of great taxonomic value. Among them, the robust M2 is especially noteworthy and documented the early presence of U. a. taubachensis in Europe. The specific cranial and dental characters of many Late Pleistocene brown bears, especially from periglacial areas, cannot be disputed. There is given a good evidence from Central and East Europe to north Siberia ( Musil 1964; Ballesio 1983; Baryshnikov & Boeskorov 2005; Marciszak et al. 2019b) that the bears from the Last Glacial were characterised by a unique combination of characters, unknown in extant representatives of this species. The problem is that, with exception of some Eemian sites (e.g. Taubach in Germany, Dziadowa Skała in Poland or Chlupáčova sluj in the Czech Republic), the Late Pleistocene record of brown bears is rather fragmentary not allowing characterising sufficiently the population variability. We therefore decided to leave open the question of the taxonomic status of Late Pleistocene bears, and used informal taxa for describing the morphological characters of the specimens studied. We use the term U. a. taubachensis for a large form corresponding to the traditional concept of ‘ U. a. priscus ’ (leaving aside the fact that these phenotypic characteristics do not fit the holotype of U. a. priscus itself). Ursus arctos arctos is restricted to the European Late Pleistocene brown bears, identical to the recent, nominotypical subspecies U. a. arctos .