Geologia CroaticaGeologia Croatica First record of Dicrostonyx (Rodentia, Mammalia) in the Late Pleistocene/?Holocene sediments of Croatia  Jadranka Mauch Lenardić Institute for Quaternary Palaeontology and Geology, Croatian Academy of Sciences and Arts, Ante Kovačića 5/II, HR–10000 Zagreb, Croatia; (jml@hazu.hr) doi: 10.4154/gc.2013.15 AB STRA CT The fossil remains of lemmings (Dicrostonyx sp.) have been discovered for the first time in Croatia. The small sam- ple of 11 teeth (M1-3 and M1) originate from the Late Pleistocene/?Holocene sediments from the Romualdova pećina site (Western Istria). The resemblance has been observed in morphological data, while some metrical parameters dif- fer slightly in comparison to the findings from some other European localities, for example from Poland, Austria and France. The mean length value of M1s from the Croatian sample is higher than the Austrian (Nixloch and Merken- stein Caves), and French (Bois Roche site) ones, while it is the same for similar specimens from the Polish Late Gla- cial, but smaller than the Polish Holocene findings, respectively. The differences in A/L and C/W1 indices have also been observed between samples from the Romualdova pećina and Polish samples of Late Glacial and Holocene age. As a good indicator of a cold and dry climate, the lemmings from the Romualdova pećina give support to the con- clusion that this part of Europe was a refugial region for this and some other small mammal species during the ex- pansions of the ice cover, and reflect Quaternary environmental fluctuations, which were frequent and pronounced at the end of this period. Keywords: lemming, Dicrostonyx, teeth, morphometric analyses, Late Pleistocene, Romualdova pećina, cave, Croatia tocene sediments of the Romualdova pećina (Romualdo’s or Lomardo’s Cave, in further text Romualdova) locality for the first time. The cave is situated on the southern side of the Limski (Lim) Channel near Rovinj in western Istria (Fig. 1), and has been an interesting palaeontological site since the1960s (MALEZ, 1962, 1968, 1978; KOMŠO, 2011). The cave is formed in the Upper Jurassic limestones, with the entrance at 120 m a. s. l. It is more than 100 m long, and has the shape of underground corridor which is in some places widened into elongated halls (MALEZ, 1962). During field work in 1961, 1962, and 1973, when MALEZ and his team made probe excavations (Fig. 2a, b), very abundant fossil material was collected, in which bear (Ursus spelaeus and U. arctos) remains were the most numerous, in addition to other taxa listed in Figure 2c (after Malez’s original deter- 1. INTRODUCTION In many areas of the European continent, lemmings (Di- crostonyx sp.), as extremely boreal taxa, had disappeared dur- ing the last interglacial (Riss-Würm) period, and in two waves recolonized central and southern Europe from the Scandina- vian region. The first recolonization occured around 40 ka BP, when they reached the Alps, Carpathians and Caucasus Mts., while during the second widening of their areas (cca. 20 ka BP), lemmings migrated farther south, in the Carpathian basin and southern parts of western Europe, respectively (KOR- DOS, 1990). During these areal expansions, Dicrostonyx also inhabited the region of present day western Croatia. Results of morphometric analyses of Dicrostonyx teeth are presented here. This taxon is determined in the Late Pleis- Geologia Croatica 66/3 183–189 3 Figs. 2 Tabs. Zagreb 2013 Geologia Croatica 66/3Geologia Croatica 184 mination; MALEZ, 1968). The results of geometric-morpho- metric analyses of the Romualdova bear molars were pre- sented by SEETAH et al. (2012), where the authors quoted the similarities/differences of bear populations (beside Romualdova, the Vindija sample has also been investigated) through time and space. Detailed revision of the macrofau- nal remains is now in progress (MIRACLE et al., in prepa- ration). Molars have been separated recently from the small mammal sample and prepared for preliminary analyses by the present author. In this material, the arvicolines prevail, among which voles are the most abundant: Arvicola amphib- ius (=terrestris), Myodes (=Clethrionomys) glareolus, Mi- crotus ex gr. arvalis/agrestis, M. ex gr. subterraneus/multi- plex, M.oeconomus, and Chionomys nivalis, but other „micromammals“ such as Chiroptera and Eulipotyphla (=In- sectivora; genera Erinaceus and Talpa, Fig. 2c) are also rep- resented. As previously mentioned, one of the most interest- ing discoveries is lemming teeth (Dicrostonyx sp.) recorded for the first time from the Late Pleistocene and perhaps Holocene sediments of Croatia. In 2007 and 2008, KOMŠO and his team started systematic excavations in the cave (KOMŠO, 2011), and abundant fossil material, collected dur- ing these field-campaigns, still waits to be palaeontologically analysed. The lemmings are small arvicoline rodents represented by 12 living species, adapted to cold and dry habitats, hav- ing a holarctic distribution today. Recent DNA techiques and analyses allow different phylogenetic studies on the contem- porary lemming populations (e. g. FEDOROV, 1999; PROST et al., 2010; and references therein), that provide new data on the evolutionary rates and phylogenetic relationships of this taxa. The results of mtDNA analyses for the populations from the Canadian Arctic, Greenland and eastern Beringia have been presented by FEDOROV & STENSETH (2002). The authors argued about the division of different phylo- groups (Canadian Arctic and eastern Beringia), and gave the possible time of their divergence at 115 – 10 ka. The hypoth- esis of ice-free areas during the last glaciation, beside the data of the Dicrostonyx findings, is also supported by the fossil specimens of other good indicators of the tundra en- vironments such as saiga (Saiga tatarica) and muskoxen (Ovibos moschatus; FEDOROV & STENSETH, 2002). The climatic changes at the end of the Pleistocene and beginning of Holocene also favoured possible habitat changes, which had a direct influence on the distribution and hence on the evolutionary rates in many small mammal taxa, including lemmings. During the Pleistocene, especially the Late Pleis- tocene, alternation of glacial and interglacial periods resulted with restricted areas of the particular species into refugial Figure 1: Geographical location of Romualdova pećina (western Istria) ; internet source: http://www.maps-for-free.com/ Jadranka Mauch Lenardić: First record of Dicrostonyx (Rodentia, Mammalia) in the Late Pleistocene/?Holocene sediments of Croatia Geologia Croatica 185 ones (FEDOROV & STENSETH, 2002). The Balkan penin- sula is one of the regions of interest for such research (MIR- ACLE et al., 2010), while migrations of various large and small mammals were defined by the particular geographic position of this part of Europe. In his work MALEZ (1986, p. 106) wrote that the most southern locality of Dicrostonyx torquatus (arctic or collared lemming) on the territory of the former Yugoslavia was Babja jama Cave near Dob at Domžale in Slovenia (46°03′ N and 14°30′ E). The new dis- coveries from the Croatian Romualdova site (45° 7’ 44’’ N and 13°14’ 17’’ E) move this line farther south. The species of the genus Dicrostonyx are not the members of the present day fauna of Croatia. 2. GEOLOGICAL SETTINGS MALEZ (1962, 1968, 1978) provided sedimentary and stratigraphic sequences for Romualdova (Fig. 2), and wrote that fossil remains, including abundant small mammal find- ings, appeared at layer c in the test-pits made in 1961 and 1962. This layer was most probably sedimented during the Würm III Stadial (MALEZ, 1968). Furthermore, beside an- imal remains, stone artefacts, traces of hearths, one human tooth has also been discovered proving the presence of Pa- laeolithic men in the cave (MALEZ, 1968, 1978). The most complex profile of the Quaternary layers was discovered in test-pit I (Fig. 2). After recent investigations conducted by KOMŠO (2011), and palaeontological analyses in progress, a more precise stratigraphic position of the particular layers will be soon defined. 3. MATERIAL AND METHODS A small sample of 153 upper and lower arvicoline teeth, sep- arated from other faunal remains which comprise several hundreds of specimens, has been morphometrically anal- ysed. In this collection 11 molars (mainly M1 - 3, and M1; Fig. 3b, c) belong to the genus Dicrostonyx. Unfortunatelly we do not know the exact stratigraphic position of these fossil remains, and worse still, it is not known from which exca- vation campaign year they come from. Therefore, it is as- sumed that they belong to the faunal sample from layer c, not only because the majority of the specimens which are stored at the Institute’s collections were found in the 1960’s, but also because MALEZ (1978) emphasized that this is the Pleistocene layer with abundant fossil findings. Furthermore, Figure 2: Romualdova pećina: a – ground -plan; b – profile; c – stratigraphic profile/ layers with determined fauna. LEGEND: layer a – dark reddish-brown compact clay with small limestone particles, layer b – dark yellow-brown compact clay, layer c – dark brown clay with limestone debris, human traces, and abundant fossil re- mains, layer d – yellow-reddish fat clay with out limestone debris, layer e – brown- ish-yellow fine-grained sand with inclu- sions of reddish clay, layer f – sinter depo- sit, Jl –Jurassic limestone (after: MALEZ, 1968). Geologia Croatica 66/3Geologia Croatica 186 all collection/inventory numbers contain only locality ab- breviations and the ordinal number. Taxonomic determina- tions, molar terminology and metrical methods were used after RABEDER (1981), NADACHOWSKI (1982) and NA- GEL (1992). Measurements: The overall tooth length (L), the length of the anteroconid complex (a), width of the posterior lobus (W), c (distance be- tween LRA5 and BRA5 inside the enamel wall), w1 (width of anterior part between LSA6 and BSA5) have been meas- ured (Fig. 3a), and A/L and C/W1 (ratios were multiplied by 100) indices were calculated (according to NADACHOWSKI, 1982). All measurements are in milimetres (mm). Morphotypes: Morphotypes of M1 have been determined and named after NADACHOWSKI (1982, p. 26–27) for the species Di- crostonyx gulielmi. The fossil material is stored at the Institute for Quater- nary palaeontology and geology of the Croatian Academy of Sciences and Arts in Zagreb. Abbreviations: Used abbreviations are: sin. (sinister = left), dext. (dex- ter = right), M1, M2, M3 (first, second, third lower molar), M1 (first upper molar), BSA5 (fifth buccal salient angle), LSA6 (sixth lingual salient angle), BRA5 (fifth buccal re- entrant angle), LRA5 (fifth lingual re-entrant angle), T5, T7 (fifth, seventh triangle), luv-side (anterior side of a salient angle), lee-side (posterior side of a salient angle), ka (thou- sands of years), n (number of specimens), min. (minimum value), max. (maximum value), χ (mean value), Rp (Romual- dova pećina). Figure 3: Molars of Dicrostonyx sp. from the Romualdova pećina Late Pleis- tocene layers: a – measurement points on the first lower molar (not to scale; drawing partly after: NADACHOWSKI, 1982, Fig. 2/3); b – mandible with M1 and M2 dext. (collection number: Rp/21); c – first upper right molar (M1 dext.; collection number: Rp/23). Table 1: Metrical values (L, a, W, c, w1, A/L, C/W1) for the Dicrostonyx sp. molars from Romualdova pećina, Late Glacial and Holocene Polish samples of D. gulielmi (NADACHOWSKI, 1982), and Late Pleistocene D. torquatus sample from Bois Roche site in France (SESÉ & VILLA, 2008). For abbreviations see the text. Measurements and indices (M1) Romualdova pećina Dicrostonyx sp. Poland (Holocene) D. gulielmi Poland (Late Glacial) D. gulielmi Bois Roche, France (Late Pleistocene) D. torquatus n min.-max. (c) n min.-max. (c) n min.-max. (c) n min.-max. (c) L 5 3.37–3.91 (3.63) 10 3.76–4.06 (3.89) 9 3.43–3.81 (3.63) 7 3.17–3.83 (3.55) a 5 1.97–2.4 (2.17) – – – – – – W 4 1.24–1.42 (1.31) – – – – 7 1.18–1.52 (1.34) c 5 0.19–0.25 (0.22) – – – – – – w1 3 0.95–1.07 (0.99) – – – – – – A/L 5 57.43–62.31 (59.75) 10 55–61 (58) 9 56–61 (58) – – C/W1 3 20–23.36 (21.4) 10 10–30 (23) 9 10–36 (21) – – 4. RESULTS Order Rodentia BOWDICH, 1821 Superfamily Muroidea, ILLIGER, 1811 Family Cricetidae FISCHER VON WALDHEIM, 1817 Subfamily Arvicolinae GRAY, 1821 Tribe Dicrostonychini KRETZOI, 1955 Genus Dicrostonyx GLOGER, 1841 Dicrostonyx sp. (Figs. 3a, b, c) Material: 11 molars (3 M1 sin.; collection numbers: Rp/ 118, 124 and 125), 2 M1 dext. (collection numbers: Rp/21 Jadranka Mauch Lenardić: First record of Dicrostonyx (Rodentia, Mammalia) in the Late Pleistocene/?Holocene sediments of Croatia Geologia Croatica 187 JANIAN & KOENIGSWALD (1977), and from the afore- mentioned Nixloch Cave, a smaller sample of this genus has also been morphometrically analysed (NAGEL, 1992). In the same article NAGEL gave the data (so called morphody- namic index) for other Austrian sites: Kemathenhöhle (30 ka BP), Geiβenklösterle (31 ka BP) and Kleine Scheuer (13.25 ka BP). The latter author analysed the D. gulielmi findings (NAGEL, 1997) from the Merkenstein Cave (Lower Austria) as well, quoting the possibility that the findings be- long to the subspecies D. gulielmi gulielmi. The length of M1s from this site shows that they are somewhat smaller than those from Nixloch (Tab. 2). The age of the Merkenstein lo- cality is the same as for Nixloch, or even younger. The Romualdova teeth show greater length values for the first upper and first lower molars than the aforementioned Aus- trian ones. From the Würmian/Late Glacial faunal list of the Knochenhöhle site near Kapellen in southeastern Austria (~14 – 10 ka BP; FLADERER, 2000) Dicrostonyx (i. e. D. torquatus f. gulielmi) is also known. After NADACHOWSKI (1982) there is a great morpho- logical variability on M1s (in species D. gulielmi), from more primitive morphotypes (e. g. A) with less in number and more confluent triangles to progressive types (G, H, I) with less confluent and up to eight, even nine triangles. Other parts of M1s also show some variations, such as connections be- tween two triangles etc. In the Croatian sample, variations of the anteroconid complex have not been observed, due to the low number of discovered M1s, and all teeth have eight closed triangles (not confluent). NADACHOWSKI (1982, p. 31) discovered decreasing length values of M1s (for the species D. gulielmi, from the Lower to Upper Pleniglacial, and to the Late Glacial, respec- tively). In the samples from the Holocene (e. g. Niedostepna, Tunel Wielki, Ciasna, etc.) the M1 length increases again. Furthermore, in the Polish sample A/L indices fluctuate be- tween 56 and 58 (original values are 0.56 and 0.58, because they were not multiplied by 100; author’s remark), and sig- nificant differences occur between Upper Pleniglacial and Holocene. C/W1 (NADACHOWSKI originally signed this ratio as C3/W3; author’s remark) the coefficient also differs statistically (idem, p. 33). The Romualdova sample shows the highest A/L values, while the C/W1 index is the same as in the Late Glacial Polish sample (Tab. 1). Furthermore, Di- crostonyx molar length from Romualdova has a higher mean value in comparison to the early Late Pleistocene D. torqua- tus sample from Bois Roche (France; SESÉ & VILLA, 2008), while for the width it is just the opposite (Tab. 1). The record of D. torquatus from Hungary (e. g. in Jank- ovich Cave, western Hungary; JÁNOSSY, 1986) is of Late Glacial age, while it lacks in Holocene layers completely. The same author gives detailed faunal lists for other Hungar- ian Late Pleistocene localities (e. g. Pilisszántó /10 km NNE from Budapest/, Remete Cave /NW from Budapest/, Bivak Cave /W Hungary/, Tokod-Nagyberek /W from Tokod vil- lage/, Gencsapáti /N from Szombathely/, Süttő locality no. 6 /~120 km NW from Budapest/), where the lemmings were present in different stages and substages. No morphometric data are avaliable in the work of JÁNOSSY (1986). The Table 2: Minimum, maximum and mean values for M1-3 and M1 length of Dicrostonyx sp. from Romualdova pećina in comparison to the Austrian samples (NAGEL, 1992, 1997). Locality Length (L) n min.-max. c M1 Romualdova pećina 5 3.37–3.91 3.63 Nixloch cave 10 3.17–3.73 3.5 Merkenstein cave 50 2.25–3.63 3.15 M2 Romualdova pećina 4 1.71–1.93 1.81 Nixloch cave 23 1.6–2 1.8 M3 Romualdova pećina 1 1.92 - Nixloch cave 11 1.45–2.32 1.71 M1 Romualdova pećina 2 2.64–2.67 2.66 Nixloch cave 16 2.2–2.78 2.42 Merkenstein cave 50 2.03–2.65 2.42 and 22), 3 M2 sin. (collection numbers: Rp/118, 124 and 125), 1 M3 sin. (collection number: Rp/125), 1 M1 sin., and 1 M1 dext. (part of the skull; collection number: Rp/23). Description: The molars of Dicrostonyx are rootless, without cement, with leptoknem enamel band (luv-side /con- cave/ is thicker than the lee-side /convex/; see the Abbrevia- tions) which is on all anticlines and apexes discontinuous (so called enamel-free areas; Fig. 3). The first lower molars (M1) from the Croatian sample consists of posterior lobus, eight triangles and anterior cap. On the basis of number and shape of the anteroconid complex AGADJANIAN (1976) proposed four morphotypes (I – IV) for the known Dicros- tonyx species, which were also presented in the Austrian lo- cality Nixloch (cave near Losenstein-Ternberg in Upper Aus- tria; age: 18.310 ± 580 y BP /14C/; NAGEL, 1992). In the small sample of five M1s from Romualdova the morphotypes have been determined after NADACHOWSKI (1982; for the species D. gulielmi). Significant variations of the ante- roconid complex could not be observed, and all five molars have been determined as pertaining to the morphotype E. The results of the metrical analyses are presented in Ta- bles 1 and 2. 5. DISCUSSION The dentitions of lemmings show great individual variations (especially on M1s and M3s) on which basis some authors differentiated two species (Dicrostonyx gulielmi and D. henseli; HINTON, 1910, 1926; cited in: NADACHOWSKI, 1982). JÁNOSSY (1954) wrote that these two species rep- resent only variations of the species D. torquatus. The evolution of the upper teeth of Dicrostonyx from the Middle Pleistocene to recent was presented by AGAD- Geologia Croatica 66/3Geologia Croatica 188 southernmost locality with lemming remains is near Veszprem (about 47° N). GUILDAY (1963) wrote about two species of collared lemmings from the palearctic Pleistocene sites, and as the common Eurasian fossils, he stressed D. gulielmi (localities: Hutton Cave, Somersetshire, England) as the Late Pleis- tocene form of the recent D. torquatus. The same author also mentioned some other Old World Pleistocene Dicrostonyx sites in England, Ireland, France, Germany, Poland, and former Czechoslovakia. As previously mentioned, the lemmings had a wide dis- tribution in Eurasia during the Late Pleistocene. The south- ernmost localities have been discovered in the southwestern part of France, Switzerland, Hungary and Ukraine (JÁNOSSY, 1954, VILLA et al., 2010), and on the North American continent these animals were distributed from Alaska to the Great Lakes (GUILDAY, 1963; REPENNING et al., 1964, cited from: NADACHOWSKI, 1982). On the North American continent, the most southern localities have been recorded in Pennsylvania (from ~40° to ~42° N). Con- temporaneous areas of the lemmings are in the arctic and sub-arctic tundra and forest-tundra in the palearctic (cir- cumpolar), from the White Sea, western Russia, to the Chu- kotski Peninsula, north-east Siberia, and Kamchatka; includ- ing Novaya Zemlya and the New Siberian islands, Arctic Ocean (WILSON & REEDER, 2005), but excluding Wran- gel Island (GROMOV & ERBAEVA, 1995; PAVLINOV et al., 2002). TSYTSULINA et al. (2008) quoted the fact that once it was believed that Dicrostonyx torquatus „encompass most or all New World populations, but karyotypic and breeding evidence supports the strict application of D. torquatus for only Eurasian populations“ (see also: WILSON & REEDER, 2005, and references therein). The habitat that Dicrostonyx prefers is dry and stony tundra. It is simpatrical with another lemming vole, Lemmus, which occupies the same ecological niches. The impact of the herbivorous mammals, including Di- crostonyx, on the arctic vegetation as an important lemming- plant interaction was emphasized by OKSANEN et al. (2008). The lemmings feed on grasses, sedges and other green vegetation in summer, and twigs of willow, aspen and birches in winter, as mentioned for one representative of the genus, Dicrostonyx groenlandicus (so called northern col- lared lemming) which lives in the tundra regions of northern Canada, Alaska and Greenland. The most common lemming predators are snowy owls (Bubo scandiacus), gulls, wolver- ines, the Arctic foxes and the polar bears (http://en.wikipe- dia.org/wiki/Northern_collared_lemming). Further detailed studies of the faunal remains from Ro­ mualdova will provide the answers as to which layers/age the Dicrostonyx discoveries on this site originate, and the specific determinations will be possible on the larger sample as the result of the systematic excavations which have been performed in previous years. Furthermore, it will be deter- mined whether the Romualdova lemmings are more similar to the representatives of the recent species D. torquatus, or more probably, that they belong to D. gulielmi. ACKNOWLEDGEMENT The author is grateful to Dr. Gloria CUENCA BESCÓS and an anonymous reviewer for their valuable comments and help improving the earlier draft of the manuscript. This study was part of the Institute’s projects by the Ministry of Sci- ence, Education and Sports of the Republic of Croatia, Pro- ject 101-2690680-2270 „Correlation of the Palaeolithic, Me- solithic and Neolithic of the continental and coastal Croatia“ (from 2007 till 2013). REFERENCES AGADJANIAN, A. (1976): Die Entwicklung der Lemminge der zentral- en und östlichen Paläoarktis im Pleistozän.– Mitteilungen der Bay- erischen Staatssammlung für Paläontologie und historischen Geolo- gie, 15–16, 53–64, München. AGADJANIAN, A. & KOENIGSWALD, W.v. (1977): Merkmalsver- schiebung an den oberen Molaren von Dicrostonyx (Rodentia, Mam- malia) im Jungtertiär.– Neues Jahrbuch für Geologie und Paläontolo- gie/Abhandlungen, 153, 34–49, Stuttgart. FEDOROV, V.B. (1999): Contrasting mitochondrial DNA diversity esti- mates in two sympatric genera of Arctic lemmings (Dicrostonyx: Lemmus) indicate different responses to Quaternary environmental fluctuations.– Proceedings of the Royal Society, B, 266, 621–626, London. FEDOROV, V.B. & STENSETH, N. CHR. (2002): Multiple glacial refu- gia in the North American Arctic: inference from phylogeography of the collared lemming (Dicrostonyx groenlandicus).– Proceedings of the Royal Society London, ser. B, 269, 2071–2077, London. FLADERER, F.A. (2000): Late Quaternary vertebrate taphocoenoses from cave deposits in southeastern Austria: responses in a periglacial set- ting.– In: HART, M.B. (ed.): Climates: Past and Present. Geological Society, Special Publications, London, 181, 199–213. GROMOV, I.M. & ERBAEVA, M.A. (1995): The Mammals of Russia and Adjacent Territories. Lagomorphs and Rodents.– Zoologicheskii Institut RAN, Sankt Peterburg, 522 p. [in Russian] GUILDAY, J.E. (1963): Pleistocene zoogeography of the lemming, Dicro- stonyx.– Evolution, 17, 194–197. JÁNOSSY, D. (1954): Fossile Microtinae aus dem Karpathenbecken. I. Lemminge.– Annales Historico-Naturales Musei Nationalis Hungari- ci, Nov. Ser., 5, 39–48, Budapest. JÁNOSSY, D. (1986): Pleistocene vertebrate faunas of Hungary.– Akadémiai Kiadó, Budapest, 208 p. KOMŠO, D. (2011): Romualdova pećina/The Romuald's Cave.– In: MI- HE LIĆ, S. (ed.): Arheologija i turizam u Hrvatskoj/Archaeology and Tourism in Croatia, Arheološki muzej u Zagrebu, Zagreb, 356–361 [in Croatian and English]. KORDOS, L. (1990): The evolution of Upper Pleistocene voles in Central Europe.– In: FEJFAR, O. & HEINRICH, W.-D. (eds.): International Symposium Evolution, Phylogeny and Biostratigraphy of Arvicolids (Rodentia, Mammalia), Rohanov (Czechoslovakia) May1987, 275–284, Praha. MALEZ, M. (1962): Romualdo Cave – a new significant Pleistocene site in Istria.– Bulletin Scientifique, 7, 6, 159–160, Zagreb. MALEZ, M. (1968): Tragovi paleolita u Romualdovoj pećini kod Rovin- ja u Istri [Paläolitische Spuren in der Romualdohöhle bei Rovinj in Istrien].– Arheološki radovi i rasprave JAZU, 6, 7–26, Zagreb [in Croatian with German summary]. MALEZ, M. (1978): Paleontološka i kvartargeološka istraživanja u 1973. godini [Paleontological and geological researches of Quaternary in the year 1973].– Ljetopis Jugoslavenske akademije znanosti i umjet- nosti, 78, 559–572, Zagreb [in Croatian]. Jadranka Mauch Lenardić: First record of Dicrostonyx (Rodentia, Mammalia) in the Late Pleistocene/?Holocene sediments of Croatia Geologia Croatica 189 MALEZ, M. (1986): Die quartären Vertebraten-Faunen in der SFR Jugo- slawien.– Quartärpaläontologie, 6, 101–117, Berlin. MIRACLE, P.T., MAUCH LENARDIĆ, J. & BRAJKOVIĆ, D. (2010): Last glacial climates, ‘‘Refugia’’, and faunal change in Southeastern Europe: Mammalian assemblages from Veternica, Velika pe ćina, and Vindija caves (Croatia).– Quaternary International, 212, 137–148. doi:10.1016/j.quaint.2009.06.003 NADACHOWSKI, A. (1982): Late Quaternary Rodents of Poland with Special Reference to Morphotype Dentition Analysis of Voles.– Polska Akademia Nauk, Zakład Zoologii Systematycznej i Doświadczal nej, Państwowe Wydawnictwo Naukowe – Oddział w Krakowie, 109 p. NAGEL, D. (1992): Die Arvicoliden (Rodentia, Mammalia) aus dem Nix- loch bei Losenstein-Ternberg (O.Ö.).– Mitteilungen der Kommission für Quartärforschung der Österreichischen Akademie der Wissen- schaften, 8, 153–187, Wien. NAGEL, D. (1997): Dicrostonyx gulielmi (Lemming) aus der Höhle von Merkenstein/Niederösterreich.– Wissenschaftliche Mitteilungen aus dem Niederösterreichischen Landesmuseum, 10, 225–230, Wien. OKSANEN, T., OKSANEN, L., DAHLGREN, J. & OLOFSSON, J. (2008): Arctic lemmings, Lemmus spp. and Dicrostonyx spp.: inte- grating ecological and evolutionary perspectives.– Evolutionary Ecology Research, 10, 415–434. PAVLINOV, I.Ya., KRUSKOP, S.V., VARSHAVSKY, A.A. & BORIS- SENKO, A.V (2002): Terrestrial mammals of Russia. An identifica- tion manual.– KМK Press, 298 p. [in Russian]. PROST, S., SMIRNOV, N., FEDOROV, V.B., SOMMER, R.S., STILLER, M., NAGEL, D., KNAPP, M. & HOFREITER, M. (2010): Influence of Climate Warming on Arctic Mammals? New Insights from Ancient DNA Studies of the Collared Lemming Dicrostonyx torquatus. – PloS ONE, 5 (5), e10447. doi: 10.1371/journal.pone.0010447 RABEDER, G. (1981): Die Arvicoliden (Rodentia, Mammalia) aus dem Pliozän und dem älteren Pleistozän von Niederösterreich.– Beiträge zur Paläontologie von Österreich, 8, 1–373. SEETAH, T.K., CARDINI, A. & MIRACLE, P.T. (2012): Can morphos- pace shed light on cave bear spatial-temporal variation? Population dynamics of Ursus spelaeus from Romualdova pećina and Vindija, (Croatia).– Journal of Archaeological Science, 39, 500–510. doi: 10.1016/j.jas.2011.10.005 SESÉ, C & VILLA, P. (2008): Micromammals (rodents and insectivores) from the early Late Pleistocene cave site of Bois Roche (Charente, France): Systematics and paleoclimatology.– Geobios, 41, 399–414. TSYTSULINA, K., FORMOZOV, N. & SHEFTEL, B. (2008): Dicros- tonyx torquatus.– In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. . Downloaded on 08 March 2013 VILLA, P., SÁNCHEZ GOÑI, M.F., CUENCA BESCÓS, G., GRÜN, R., AJAS, A., GARCÍA PIMIENTA, J.C. & LEES, W. (2010): The ar- chaeology and paleoenvironment of an Upper Pleistocene hyena den: An integrated approach.– Journal of Archaeological Science, 37, 919–935. WILSON, D.E. & REEDER, D.M. (2005): Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed.).– Johns Hopkins University Press, 2, 142 p. Internet source: http://en.wikipedia.org/ wiki/Northern_collared_lemming. Downloaded on 01 July 2013 Manuscript received March 15, 2013 Revised manuscript accepted July 26, 2013 Available online October 16, 2013