Gulo gulo ( Linnaeus, 1758 )

Marciszak, A, Stefaniak, K & Gornig, W, 2017, Large mammals (carnivores, artiodactyls) from Solna Jama Cave (Bystrzyckie Mts, Southwestern Poland) in the context of faunal changes in the postglacial period of Central Europe, Palaeontologia Electronica (Bellingham, Wash.) 11 (4), pp. 1-37 : 7-12

Gulo gulo ( Linnaeus, 1758)

Figures 4-6 , Appendix 8

Specimens. Seventy six bones belong to one individual: cranium without left zygomatic arch and posterior part of neurocranium and with left I1-M1 (P4 worn) and right I1-C1 and P2-M1 (JSJ/Gg/1-1); small piece ofv the left mandible with p1, p3 and m1 (JSJ/Gg/1-2); right mandible with i3 and p2-m2 (now p4-m2 are strongly worn) and ramus fragment (JSJ/Gg/1-3); damaged, left scapula (JSJ/ Gg/1-4); damaged shaft of left humerus with fragment of proximal epiphysis (JSJ/Gg/1-5); right radius (JSJ/Gg/1-6); shaft fragment of the right tibia with a piece of proximal epiphysis (JSJ/Gg/1- 7); right fibula (JSJ/Gg/1-8); damaged, left coxae (JSJ/Gg/1-9); damaged cervical (JSJ/Gg/1-10); 3 caudals (JSJ/Gg/1-11 – 13); 3 costaes without distal epiphysis (JSJ/Gg/1-14 – 16); damaged baculum (JSJ/Gg/1-17); right calcaneus (JSJ/Gg/1-18); right talus (JSJ/Gg/1-19); left pisiform (JSJ/Gg/1-20); right pisiform (JSJ/Gg/1-21); left navicular (JSJ/Gg/ 1-22); left cuboid (JSJ/Gg/1-23); left cuneiform I (JSJ/Gg/1-24); right cuneiform II (JSJ/Gg/1-25); right cuneiform III (JSJ/Gg/1-26); left metacarpal I (JSJ/Gg/1-27); left metacarpal II (JSJ/Gg/1-28); right metacarpal III (JSJ/Gg/1-29); left metacarpal IV without distal epiphysis (JSJ/Gg/1-30); left metacarpal V (JSJ/Gg/1-31); left metatarsal I without proximal epiphysis (JSJ/Gg/1-32); left metatarsal II (JSJ/Gg/1-33); left metatarsal III (JSJ/Gg/1-34); left metatarsal IV (JSJ/Gg/1-35); right metatarsal V (JSJ/Gg/1-36); 14 phalanges I (JSJ/Gg/1-37 – 50); 10 phalanges II (JSJ/Gg/1-51 – 60); 9 phalanges III (JSJ/Gg/1-61 – 69); 7 sesamoides (JSJ/Gg/1-70 – 76).

Measurements. Cranium (JSJ/Gg/1): 1, (185.00) mm; 4, 84.70 mm; 6, 91.56 mm; 7, 55.26 mm; 8, 75.24 mm; 9, 94.65 mm; 10, 65.47 mm; 11, 50.37 mm; 12, (122.00) mm; 13, 30.16 mm; 14, 52.96 mm; 15, 84.60 mm; 16, 66.43 mm; 17, 21.3 mm; 18, 56.28 mm; 19, 47.46 mm; 20, 57.75 mm; 21, 42.04 mm; 25, 30.83 mm; 26, 25.98 mm; 31, 62.15 mm; 32, 65.70 mm; I1-L, 8.09 mm (right), 8.40 mm (left); I1-B, 4.53 mm (right), 4.34 mm (left); I2-L, 8.79 mm (right), 8.86 mm (left); I2-B, 4.86 mm (right), 4.41 mm (left); I3-L, 10.87 mm (right), 10.51 mm (left); I3-B, 7.97 mm (right), 7.82 mm (left); C1- L, 14.48 mm (right), 14.57 mm (left); C1-B, 11.31 mm (right), 11.46 mm (left); P1-L, 5.13 mm (left); P1-B, 4.56 mm (left); P2-L, 9.16 mm (right), 9.21 mm (left); P2-B, 9.49 mm (right), 6.68 mm (left); P3-L, 13.25 mm (right), 13.27 mm (left); P3-Ba, 7.33 mm (right), 7.37 mm (left); P3-Bp, 8.68 mm (right), 8.73 mm (left); P4-L, 25.16 mm (right), 25.18 mm (left); P4-Ba, 14.19 mm (right), 14.36 mm (left); P4-Bp, 10.38 mm (right); M1-L1, 9.59 mm (right), 9.36 mm (left); M1-L2, 7.39 mm (right), 6.99 mm (left); M1-L3, 8.52 mm (right), 8.47 mm (left); M1-B, 16.14 mm (right), 15.98 mm (left). Mandible (JSJ/Gg/1-2/3): i3-L, 5.95 mm (right); i3- B, 6.28 mm (right); p1-L, 5.08 mm (left); p1-B, 4.63 mm (left); p2-L, 7.92 mm (right); p2-B, 6.11 mm (right); p3-L, 9.97 mm (right), 9.91 mm (left); p3-Ba, 6.04 mm (right), 6.01 mm (left); p3-Bp, 7.78 mm (right), 7.89 mm (left); p4-L, 14.57 mm (right); p4- Ba, 6.98 mm (right); p4-Bp, 9.94 mm (right); m1-L, 26.41 mm (right), 26.47 mm (left); m1-L-tri, 20.48 mm (right), 20.63 mm (left); m1-L-tal, 5.06 mm (right), 5.12 mm (left); m1-B-tri, 12.59 mm (right), 12.64 mm (left); m1-B-tal, 8.85 mm (right), 8.86 mm (left); m2-L, 5.94 mm (right); m2-B, 5.82 mm (right). Postcranial bones: Appendix 8.

Description. A detailed morphometric and morphological analysis allows to classify the found individual as a large, late Pleistocene form. All the remains, and especially the cranium, are very large ( Figures 4-6 ). The specimen from Solna Jama Cave not only considerably exceeds the recent Scandinavian specimens in all skull measurements, but also corresponds to the maximum dimensions of the largest late Pleistocene European individuals. The longitudinal diameter of C1 crowns of the specimen from Solna Jama is ca. 14.5 mm, while the transverse diameter is ca. 11.5 mm. In recent G. gulo , C1 L for males is 8.9–11.8 mm, with the mean of 10.6 mm, while B C1 is 7.1– 9.4 mm, with the mean of 8.2 mm. The respective values for females are 7.3–10.5 mm (mean = 9.5 mm) for L and 6.3–8.0 mm (mean = 7.3 mm) for B ( Döppes, 2001; Marciszak, 2012). The late Pleistocene animals were significantly larger than the recent individuals. The analysis showed that canines longer than 11.5 mm and broader than 9.0 mm (measured at the crown base) almost certainly belonged to a male. The same is suggested by the other measurements of dental and skeletal remains of G. gulo from Solna Jama. All these features, as well as the poorly expressed cranial sutures and only slightly worn teeth, indicate an adult, particularly large and robust male.

Remarks. The large Gulo gulo from the European late Pleistocene is sometimes assigned to a chronostratigraphical form/subspecies G. gulo spelaea (Goldfuss, 1818) , and distinguished from the recent form mainly in its larger size ( Goldfuss, 1818b). However, more recent authors regard it as ungrounded and classify it as G. gulo ( Döppes, 2001; Marciszak, 2012; Diedrich, 2014). Analysis of large samples from European sites showed that the late Pleistocene G. gulo had on average more robust canines (B/L for fossil G. gulo : 79.5 mm, N = 114; for recent form: 76.2 mm, N = 56). Also, premolars were slightly broader, the talonid of m1 even narrower than in the modern Gulo ( Marciszak, 2012) ( Figure 7 ).

In summary, apart from the pronouncedly larger size, the differences do not seem to be very reliable. Moreover, as demonstrated by the case of the individual from Solna Jama, even clear separation of Gulo populations into two chronosubspecies based on size is impossible. The data indicate that the differences between the large late Pleistocene form and the Holocene/extant populations are big and statistically significant. Overall, large individuals are associated with glaciation periods and smaller ones appear during interglacials. The size of the species follows the Bergmann rule (Pasitschniak-Arts and Larivière, 1995). The size increase in Gulo may also be explained by the severe continental climate with short summers and long, frosty winters that resulted in deforestation of the Sudety Mts. The reduction of plant food supply may have led G. gulo to more active predation and carnivorous foraging. Besides active hunting, it is also a kleptoparasite, and sometimes is even able to take a carcass from Canis lupus or Ursus arctos (Pasitschniak-Arts and Larivière, 1995) . Its powerful jaws and dentition allow it to crush even thick, solid elk bones. In cold habitats, where carcasses freeze very soon after animal’s death, better developed jaw musculature and broader teeth are a necessary equipment. Also a larger body can be of considerable advantage in confrontation with larger animals over food.

Historically, the first record of the species was provided already in 1837, when Pusch (1837) described the posterior part of left P4 from silt of a destroyed cave in Czarnkowa. Later, Zawisza (1882) mentioned a few wolverine remains from the Solutrenian layer in Mamutowa Cave. This was followed by a long period without fossil record; no Gulo remains were found by Rӧmer (1883) or Zotz (1939), and only Krukowski (1939) mentioned the species from sediments of Ciemna Cave. After World War II, Kowalski (1959) in his first review of the Pleistocene fauna of Poland listed all three sites. Recently, after re-examining some old German and Polish collections, and due to the new excavations, the list of G. gulo records is significantly extended.

Members of the genus Gulo are present in the fossil material from Poland from the early Pleistocene till the Holocene, and 14 sites with wolverine remains are known ( Figure 8 ). The oldest remains, dated as ca. 1.7–1.5 Ma and classified as a gracile, small and primitive G. schlosseri come from Żabia Cave ( Nadachowski et al., 2011; Marciszak, 2012). The single, damaged P4 from layer 2c of Kozi Grzbiet (Świętokrzyskie Mts.) ( Marciszak, 2012) was also assigned to this species. This find is dated as the early middle Pleistocene, most probable MIS 17 ( Kowalski, 2001). The oldest remains of G. gulo come from the lowermost layers of Biśnik Cave (layer 19ad). A single premolar was found in Biśnik Cave, in 2007 ( Marciszak et al., 2011). Based on biochronological data, those lowermost layers from both localities are estimated as MIS 10-9 ( Krajcarz et al., 2014a; Marciszak, 2014). A few isolated teeth from layers 1 and 3 of Deszczowa Cave are somewhat younger (MIS 6) ( Krajcarz and Madeyska, 2010; Krajcarz, 2012). Gulo gulo from all three above-mentioned, late middle Pleistocene sites, are morphologically distinct from those of late Pleistocene age. They represent a more primitive form, of a smaller size and slighter build.

The most numerous records come from the late Pleistocene, when the species was widespread in Europe. Most of them are well dated as the last glacial (MIS 5d – MIS 2). The remains were found in Deszczowa Cave (left mandible with p2- m2 and some postcranial bones belonging to a female, layers 8 and 9, MIS 2) ( Wojtal, 2007); Nietoperzowa Cave (fragment of left mandible with p3-p4, layer 4, MIS 3) ( Wojtal, 2007; Krajcarz and Madeyska, 2010); Mamutowa Cave (layer 5, MIS 3) ( Wojtal, 2007); Ciemna Cave (damaged calcaneus, layer C8, MIS 5) ( Krukowski, 1939). The single metatarsals II from layer 6 of Borsuka Cave ( Wilczyński et al., 2012) and layer 4 from Cave no. 4 at Birów Hill are both dated as MIS 2. Some of the remains, especially those from the Sudeten sites, have unclear stratigraphic position, however their morphology suggests that they also represent a large, late Pleistocene form. Those finds include isolated canines from Północna Duża and from layer 21 (trench V) of Niedźwiedzia Cave, as well as a dozen well-preserved long bones and metapodiales from Naciekowa Cave. Similarly, the single premolar from Cave in Czarkowa and the fragment of right mandible with p3-p4 from Mamutowa, Cave, both without stratigraphic context, are most likely of late Pleistocene age. Finally, it can be added that before World War II a complete left foot of a particularly large individual was found in the archaeological site Gródek 2 in the environs of Równe (now Riwne in Ukraine), which was then part of Poland ( Loth, 1933). All the above-mentioned sites with G. gulo are of late middle or late Pleistocene age. It seems that the find from Solna Jama is the only reliable, postglacial record of the species from Poland. Till now it was not found in any archaeological Holocene sites in Poland ( Wyrost, 1994; Sommer and Benecke, 2004). No remains were found during our detailed revision of the material from those localities (most of them).

Gulo gulo is not inherently a purely “boreal” or “tundra” species ( Döppes, 2001). Remains of this species are known from Southeast Europe ( Ukraine and Hungary) dated as the Subboreal period, but bones dated as the Middle Ages were found only in Northeast Europe (Pribaltica, Fennoscandinavia) ( Krakhmalnaya, 1999; Sommer and Benecke, 2004; Marciszak, 2012). Some authors signalled a possible occurrence of G. gulo in Northeast Poland as late as in the nineteenth century ( Hoyer, 1937). A few hunting records of the species are known from the last 300 years from areas which once belong to Poland (now W Ukraine): environs of Khmelnytskyi (49 o 25’N, 27 o 0’E), Kamianets Podilskyi (48 o 41’N, 26 o 35’E), both dating from the 1700–1750s) and an individual in the vicinity of Ovruch (51 o 19’ N, 28 o 48’ E, nineteenth century). The last specimens were killed: one just before World War I near Radomyshl (50 o 29’ N, 29 o 14’E) and another in the environs of Jarmolińce (49 o 11’N, 26 o 50’E) in 1924 ( Kuntze, 1928; Abelentsev, 1968; Daszkiewicz et al., 2005). All these are historical hunting records, and there are no preserved specimens ( Lubicz-Niezabitowski, 1934; Tomiałojć, 2003). Although the existence of a small, relict population in historic times cannot be entirely ruled out, it is more probable that those incidental appearances were migrant individuals. Gulo gulo is able to travel long distances, and its daily movements may exceed 30 km ( Haglund, 1966; Pulliainen, 1993; Pasitschniak-Arts and Larivière, 1995), while straight-line distances covered in 3 days equal to 64 km for males and 38 km for females ( Hornocker and Hash, 1981). Sraight-line distances longer than 300–350 km ( Gardner et al., 1986) are also known for G. gulo . Males are usually more mobile than females, and food availability and sexual maturity are the two major reasons for this behaviour (Pasitschniak-Arts and Lariviere, 1995).

Gulo gulo remains are quite rare in European cave localities. They were found in late Pleistocene sites mostly in the form of bones and were usually heavily outnumbered by other carnivores. The species is not regarded as a typical cave dweller and the almost complete absence of juvenile specimens indicates that caves were not used to raise cubs ( Diedrich, 2008). The main reason for accumulation of G. gulo bones inside caves seems to be predation; the cave hyena Crocuta crocuta spelaea ( Goldfuss, 1823) seems to be the major predator in this case ( Diedrich and Copeland, 2010). As remarked by Diedrich (2008, p. 128): “Carnivores were the last prey to be eaten and scavenged”, so it is more likely that specimens were killed, brought into caves but in most cases not scavenged. In the case of Solna Jama, Crocuta crocuta spelaea does not seem to be a very likely candidate for G. gulo predator, since it vanished from the territory of Poland much earlier (before the LGM), and is almost completely absent in the Sudeten sites ( Wiśniewski et al., 2009). Besides the scarce material of C. lupus , no other large predators, which may have hunted G. gulo , were found. Apart from numerous rodent gnawing marks, some deep gnawing marks were found on the humerus; both its epiphyses were probably bitten off by a large carnivore, most probably Canis lupus (Wojtal, personal commun., 2010). It is very unlikely that they were not fully fused, since the only complete radius bone has all epiphysis and sutures fully fused. At present, C. lupus is the major natural enemy of G. gulo . Despite the fact that G. gulo actively scavenges on carcasses left by C. lupus , it is risky for him. Canis lupus not only competes for food, but also kills G. gulo (Pasitschniak-Arts and Larivière, 1995) . Based on these facts it is likely that C. lupus was the predator which killed G. gulo .

Figures

FIGURE 4. Gulo gulo cranium from Solna Jama Cave (JSJ/Gg/1-1) in dorsal view (left) compared with a cranium from a large modern male from Scandinavia (right) from collection of Natural History Museum University of Wrocław (coll. no. M/500328). Scale bar equals 10 mm.

FIGURE 5. Gulo gulo cranium from Solna Jama Cave (JSJ/Gg/1-1) in ventral view (left) compared with a cranium from a large modern male from Scandinavia (right) from collection of Natural History Museum University of Wrocław (coll. no. M/500328). Note particularly powerful dentition of the individual from Solna Jama Cave in comparison with recent G. gulo. Scale bar equals 10 mm.

FIGURE 6. Metacarpals (mtcp) and metatarsals (mtts) of Gulo gulo from Solna Jama Cave. From left to right: right mtcp III (JSJ/Gg/1-29), left mtcp V (JSJ/GG/1-31), left mtts II (JSJ/Gg/1-33), left mtts III (JSJ/Gg/1-34), left mtts IV (JSJ/Gg/1-35) and right mtts V (JSJ/Gg/1-36). Scale bar equals 10 mm.

FIGURE 7. Scatter diagram showing the ratio of m1 trigonid breadth (B tri) to m1 talonid breadth (B tal) in the forms of Gulo: G. schlosseri and G. gulo. Data from Döppes (2001): late Pleistocene G. gulo and recent G. gulo; data from Marciszak (2012): G. schlosseri and late Pleistocene G. gulo (part).

FIGURE 8. Occurrence of members of the genus Gulo in the late Quaternary of Poland (after Marciszak, 2012 and references therein). Red dot: Gulo schlosseri; black dot: G. gulo from late middle Pleistocene (3-5) and late Pleistocene-Holocene (3-12). Localities: 1, Żabia Cave; 2, Kozi Grzbiet; 3, Biśnik Cave; 4, Cave no. 4 on the Birów Hill; 5, Deszczowa Cave; 6, Nietoperzowa Cave, Ciemna Cave; 7, Mamutowa Cave; 8, Borsuka Cave; 9, Cave in Czarkowa; 10, Niedźwiedzia Cave; 11, Północna Duża Cave, Naciekowa Cave; and 12, Solna Jama Cave.