Gerçek Saraç MTA,Ankara Discovery of Protaceratherium albigense (Rhinocerotidae, Mammalia) in Oligocene Saraç, G., 2003 - Discovery of Protaceratherium albigense (Rhinocerotidae, Mammalia) in Oligocene coastal deposits of Turkish Thrace - in: Reumer, J.W.F. & Wessels, W. (eds.) - DISTRIBUTION AND MIGRATION OF TERTIARY MAMMALS IN EURASIA. A VOLUME IN HONOUR OF HANS DE BRUIJN - DEINSEA 10: 509-517 [ISSN 0923-9308] Published 1 December 2003 Coastal marine deposits at Dolhan (Kirklareli, Thrace, Turkey) yielded some important remains of a land mammal, Protaceratherium albigense (ROMAN, 1912). The material consists of an upper jaw with P2-M3, a humerus, a tarsal (cuboid), two phalanges and one sesamoid bone. The marine origin is indicated by the presence of the large foraminifera Nummulites intermedius, N. fichteli and N. vascus in the same deposits. The fossiliferous horizon is mainly formed of detrital deposits of the Koyunbaba Formation, which covers unconformable the basement (Istranca Massif). The dentition of P. albigense from Dolhan is similar in size and morphology to that of the type locali- ty Sauzière-Saint-Jean (Tarn, France). This species is well known in late early to early late Oligocene localities from western Europe and Hungary. The Dolhan discovery particularly enlar- ges its geographic distribution. Together with this species, the occurrences of several mammalian taxa with European affinities (Aceratherium (Mesaceratherium) paulhiacense, Anthracotherium magnum, Elomeryx woodi and rodents) in the middle-late Oligocene deposits of Turkish Thrace suggest strong paleogeographic connections with Europe at these times. Correspondence: G. Saraç, MTA Genel Müdürlügü, Tabiat Tarihi Musesi, 06520 Ankara, Turkey; email: [email protected] Keywords: Rhinocerotidae, Oligocene, Turkey INTRODUCTION the Eocene and/or Oligocene. In the northwestern part of Turkish Thrace, Well-preserved remains of a rhinoceros, the Istranca Massif forms the major relief for- associated with some marine animals, have med of metamorphic rocks (Paleozoic to been discovered at Erikdere near Dolhan villa- Jurassic) and granitic intrusions, which cut ge, department of Kirklareli (Fig. 1). Beyond the latter in the late Cretaceous. The south- its systematic and paleogeographic interest, western slopes of this massif are covered by this record partly contributes to date the rela- Tertiary deposits that were intensively studied ted deposits and to enlighten their sedimentary during the last fifty years because of their environment. The geographic coordinates of importance for occurrences of oil, natural gas the fossil locality are given below. The rhino- and lignite, and industrial materials such as ceros remains have been collected during the quartz sands, feldspar rich clays and manga- geological mapping fieldwork in 1981-1983. nese deposits. In geological studies of The specimens are preserved in the collections Tertiary deposits several lithostratigraphic of the Natural History Museum of the Mineral units were defined, but with controversial Research and Exploration General Directorate ages, in particular for the deposits referred to (MTA) in Ankara. 509 DISTRIBUTION AND MIGRATION OF TERTIARY MAMMALS IN EURASIA DEINSEA 10, 2003 GEOLOGICAL AND HISTORICAL an early-middle Oligocene age for the latter. ANALYSIS They were the first to describe the occurrence The fossil bearing horizon is included in of marine Oligocene deposits with nummuli- coastal marine sediments deposited along the tes (N. intermedius, N. vascus and N. fichteli) southwestern shelf of the Istranca massif in in the area. According to these authors, the northwestern Turkish Thrace. The coastal det- limestone horizons, which include the num- rital facies of the Koyunbaba Formation and mulites, conformably overlie the Priabonian the unconformable overlaying recifal limesto- aged sandy-micritic limestones. ne (Sogucak Limestones) contain nummuli- Umut et al. (1984) and Saraç (1987) inclu- tes, and they are mapped as late Middle ded these deposits in the Pinarhisar Eocene. However, in his study area at Kuleli- Formation. Siyako & Kasar (1985), Kasar & Babaeski highland, Keskin (1974) attributed Aytaç (1986), and Kasar (1987) attributed the these two formations to the Oligocene. In the marine deposits near Dolhan village to the southern part of the basin (Malkara, Kesan late Eocene. Dizer (1985) noted that the and Uzunköprü areas), the detrital deposits of Islambeyli Formation (= Koyunbaba the Pinarhisar and Danisment formations are Formation) and Kirklareli Limestones (= attributed to the Oligocene (Lebküchner Sogucak Limestones) should be of early 1974). They form altogether the Paleogene Oligocene in age. The record of rhinocerotid stratigraphic units of this area. remains may contribute to clarify these con- The Koyunbaba Formation, which overlies tradictory age attributions. with angular unconformity the magmatic- metamorphic rocks of the basement, was SYSTEMATIC PALEONTOLOGY defined by Kransert & Malal (1960) and by Kasar (1987). Its type section is in the Order Perissodactyla OWEN, 1848 Magara ravine near Koyunbaba village, some Family Rhinocerotidae OWEN, 1845 five kilometers SE to the mammal locality. Its Genus Protaceratherium ABEL, 1910 thickness may reach 100 m. The recifal Protaceratherium albigense (ROMAN, 1912) Sogucak Limestones transitionally covers the (Figure 2) detrital Koyunbaba Formation. In the fossil locality, the Koyunbaba Formation shows a Distribution of the species In Europe succession of badly lithified pebble conglo- during the late early and early late Oligocene merates, sand-siltstones, clays and limesto- (MP 24-28; Antoine et al. 2003). nes, and its thickness along the Erikdere val- ley is about 40 m. The limestone horizons are Locality Erikdere, Dolhan village, Kirklareli rich in well-preserved gastropods, pelecy- department, Turkey. 1:25 000 topographic pods, echinids, corals (individual and colo- map no E18-a4, Kirklareli sheet. The fossil nies) and foraminifera. All horizons show an locality is situated, in the summer dry, intense bioturbation. The horizon that yielded Erikdere valley about one kilometer north to the rhinocerotid remains is also rich in num- the Dolhan village. The bones were unearthed mulites. Also here, the Sogucak Limestones from a horizon about 50 cm above the river overlies the Koyunbaba Formaton. bottom. The sediments are marls with sand Sirel & Gündüz (1976) presented the strati- and intercalations of gravel. The geographic graphy of these deposits in the area north of coordinates are N 41° 46' 15" and E 27° 01' Dolhan village and studied nummulites from 52". the Koyunbaba Formation and in particular from the overlaying Sogucak Limestones. In Fossiliferous horizon Pale yellow to beige their study, they suggested a Lutetian- unconsolidated sandy marls with small gra- Priabonian age for the former deposits, and vel, quite rich in gastropods, pelecypods, 510 SARAÇ: Protaceratherium from the Turkish Oligocene Figure 1 Location map of the fossiliferous area (gray square). echinid fragments and nummulites. The teeth form anticlines on the bone. The anteri- thickness of the fossiliferous horizon is about or border of the orbit is located above the three meters; it is conformably covered by anterior margin of M2. Inside the orbit, the the Sogucak Limestones. fossa sacci lacrimalis is situated in its anteri- or part. The postpalatine incision reaches the Material Left maxilla with P2-M3, left level at the middle of M2. The zygomatic humerus, left tarsal IV (cuboid), first phalanx bone is not large indicating that the skull was of the second digit, second phalanx of the probably narrow. third digit and sesamoid bone. The material is numbered as U-58-1 to U-58-6, respectively. Teeth The available P2-M3, P2 and M1 are much DESCRIPTION worn, indicating an old individual (no detail of the occlusal surface is retained). The teeth The maxilla (Fig. 2) is laterally convex. are brachydont, with conical crowns. The pre- Along the lateral face, the roots of the cheek molars and molars are nearly square, wider 511 DISTRIBUTION AND MIGRATION OF TERTIARY MAMMALS IN EURASIA DEINSEA 10, 2003 Figure 2 Protaceratherium albigense; right maxilla with P2-M3, occlusal view. than long. There is no cement. The M3 has a straight ectometaloph, resulting P2-P4 The premolars are semimolariform from the fusion of the ectoloph and the (protocone and hypocone connected by a lin- metaloph. Yet, the talon of M3 is very wide, gual bridge; Heissig 1969), further differing with a labially displaced posterior cingulum. from the molars in having strong and comple- te lingual cingulums. Their ectolophs are bro- Humerus (Fig. 3) ken. The protocone is slightly constricted Measurements in mm: Length 257.0; proxi- anteriorly on P3 and P4. There is no crochet mal transversal diameter 99.4; proximal ante- at this stage of wear. The wide and drop-like ro-posterior diameter 105.2; minimum diame- postfossette is as deep as the closed and trian- ter of diaphysis 36.6; antero-posterior diame- gular median valley. There are two distinct ter of diaphysis 41.0; distal transversal dia- labial roots and one large lingual root with meter 75.0; distal antero-posterior diameter two cavities. The size of premolars increases 61.3; transversal diameter at tuberositas del- progressively but slightly from P2 to P4 toidea 64.0. (Table 1). The humerus is small and slender. The M1-M3 All the molars have four roots and tuberculum majus and minus are broken. The they display a weak lingual cingulum.