NORTH-WESTERN JOURNAL OF ZOOLOGY 7 (2): 184-188 ©NwjZ, Oradea, Romania, 2011 Article No.: 111121 www.herp-or.uv.ro/nwjz Early Late Miocene Chilotherium (Perissodactyla, Mammalia) from Pogana (Scythian Platform) Vlad A. CODREA1,4,*, Laurenţiu URSACHI2, Daniel BEJAN3 and Cristina FĂRCAŞ4 1. Research Center for Geology of Coal Deposits and Environment Protection, University of Bucharest, 1, N. Bălcescu Av., Romania. 2. Bârlad Museum, Natural Science Branch, Bârlad, 731050, Romania. 3. Department of Geology,”Alexandru Ioan Cuza”University, Iasi, 700506, Romania. 4. Faculty of Environment Science and Engineering, “Babeş - Bolyai” University, 30 Fântânele Str., Cluj Napoca, 400294, Romania. * Corresponding author, E-mail: [email protected] Received: 06. February 2011 / Accepted: 24. May 2011 / Available online: 15. June 2011 Abstract. In Eastern Romania, Late Miocene sequences can be followed on the Scythian Platform. In several localities vertebrate remains are present, like in Pogana (Vaslui District) on the left bank of Tutova River, where there are grey clay and sand document fluvial environments that evolved around Kersonian/Meotian boundary, probably on top of Păun Formation. Carried by water streams, most of the teeth and bones found in these rocks were long rolled before burial, exposing broken and rounded margins. Among them, most relevant are some Chilotherium teeth. The presence of these rhinoceros in the early Late Miocene of Moldova has to be considered an evidence of the arrival in the oriental area of the Dacic Basin (Siret-Bug Land), of im- migrants of eastern or south-eastern origins. Key-words: Late Miocene, rhinoceros, Chilotherium, Scythian Platform, Romania. Introduction From these sands, we collected several fossil teeth and bone fragments. Within this sample the most On Scythian Platform (Săndulescu 1984), the last representative are two rhinoceros teeth, docu- sedimentary megasequence refers to the Middle menting the genus Chilotherium. The fossils are cu- Miocene-Pleistocene time span (Ionesi 1994). Nu- rated at “Vasile Pârvan” Museum, Natural Science merous exposures illustrating this geological his- Branch in Bârlad (abbreviated VPM). tory are located on south-western side of the Bâr- lad Plateau, on Tutovei Hills. These hills range from the Siret to the Bârlad rivers, limited to the Geological setting north by Racova Valley, and by Siret Plain to the south. Like in Moldavian or Moesic platforms (Ionesi This area became worldwide notorious in ver- 1994), in the Scythian Platform only the exposures tebrate paleontology due to the first finding of a of the last sedimentary megasequence are avail- nearly complete skeleton of Deinotherium proavum able for direct examination in the field. The Bârlad Eichwald, 1835 (= D. gigantissimum Ştefănescu, area illustrates the Late Sarmatian/Meotian 1891), the largest and last representative of the boundary. Due to the peculiar monocline structure European dinotheres lineage. This dinothere skele- dipping northwest to southeast, the Meotian is ton was unearthed at the end of 19th century (1890- cropping out only on the peaks of the Bârlad Pla- 1894) from sands with rather poorly known strati- teau on interfluves, while on lower altitudes one graphy (? Meotian) exposed near Mânzaţi village can observe only the older Kersonian deposits. (Zâmboanga Ibăneşti commune in Vaslui District) Kersonian sediments were already reported by Gregoriu Ştefănescu, former professor at the by Sevastos (1922) who mentioned “Sarmatian University of Bucharest (Ştefănescu 1891, 1895, molluscs” found in clays. Jeanrenaud (1971) 1899; Codrea 1994). stressed out that the Kersonian rocks occur as nar- In the same area, 20 km southwest of Mânzaţi row stripe-like exposures parallel to the river and 15 km northwest of Bârlad town at Pogana, streams from Tutovei Hills, gradually dipping there is a small local sand open pit casually mined southward under the cover of Meotian rocks. The by natives. This open pit is located near the district basal Kersonian is not cropping out in Bârlad area, road 243, on the left bank of Tutova Valley, the therefore the Bessarabian/Kersonian boundary main river stream from Tutovei Hills (Fig. 1). cannot be observed. In this region, a deltaic de- Early Late Miocene Chilotherium (Perissodactyla, Mammalia) from Pogana (Scythian Platform) 185 posit dominated by sand and clay occurs to the had been rolled before their burial, exposing top of the Kersonian sediments, belonging to the rounded margins, the majority being heavily Păun Formation (Jeanrenaud 1961). Later, surpris- damaged. Besides vertebrates, there were also ingly, Ionesi et al. (2005) used the name “Balta- freshwater molluscs (Unio sp.) shells, also broken. Păun Formation”, without defining a stratotype The upper part of this deposit is fining upward, [sic!] at Balta: “As Balta locality is located on the where fossil vertebrates were not observed. These left side of the Nistru River, we can not establish a deposits could belong to the Păun Formation, but stratotype” (pg. 430). Therefore, we will use the this assignation needs more evidence. Therefore, name introduced by Jeanrenaud (1961). we consider these rocks as Kersonian-Meotian Jeanrenaud (1971) placed the Kerson- (Fig. 1). About half meter of soil covers the Mio- ian/Meotian boundary at the level of Nuţasca- cene sands. Ruseni andesite tuff that he initially named "Nu- ţasca – Ruseni Horizon" (Jeanrenaud 1961). In fact, this tuff was earlier reported by Sevastos (1922). It Systematic Palaeontology refers to three banks of tuffaceous sandstones, 2 - 4 Order Perissodactyla Owen, 1848 m thick each one, interbedded by marl sands and Family Rhinocerotidae Gray, 1821 clays. Well represented on north-western areas of Genus Chilotherium Ringström, 1924 Tutovei Hills, this marker level is by far less clear Sub-genus Chilotherium Ringström, 1924 in others regions, where the tuff is replaced by tuf- faceous sands. To the east, the amount of volcanic Chilotherium sp. (Fig. 3 - 1, 2) input gradually decreases, passing on tuffaceous Two teeth are documenting this rhinoceros at Po- sandstone or sands, as illustrated on the geological gana, one left M2 (VPM – P/355) and one right p4 map drawn by Macarovici & Jeanrenaud (1958). (VPM – P/354). The nomenclature and way of There, the Nuţasca-Ruseni Tuff is rather indistinct. measurements follow Guérin (1980). Measure- Therefore, on the geological map published by the ments (mm). Romanian Geological Institute (folio 22 Bârlad, re- M2: Length = 50.0; Anterior width = 58.0; sponsible editor: E. Saulea, 1967), these deposits h = 32.5; are marked as belonging to “Kersonian-Meotian” p4: Length = 35.4; Anterior width = 21.0; time span. This approach is, in our opinion, more Posterior width = 20.0 realistic for this area. Description. The upper molar is the most diag- Fossil macroflora was reported by Barbu nostic. It preserves the crown, excepting the meta- (1934) and freshwater snails by Macarovici (1955). loph ending, which is broken. All roots are broken Over this level there are fluvial green clays, sandy too. The advanced wear is specific for a mature clays and sands, the latter prevailing. The highest individual. The ectoloph is waved, showing large peaks in the southern part of the region are built paracone and metacone folds. The lowest crown up on these rocks of continental origin, which can basis is located between the anterior and posterior reach about hundred meters in thickness. Pleisto- roots. From this point, the enamel is ascending cene river terraces are covering the Miocene de- both on mesial and distal directions. Strong pres- posits. sure marks can be seen both on mesial and distal Fluvial deposits are available for study in the sides, but on the first one the enamel was com- Pogana sand open pit, which yielded the fossil pletely removed during the animal lifetime. The vertebrates (Fig. 2). According to the geological protocone is strongly constricted, both mesially maps (Jeanrenaud 1961, Ionesi et al. 2005), these and distally. A strong, rounded crochet is present. deposits are early Late Miocene, close to the The antecrochet contacts the mesial metaloph wall, Kersonian/Meotian boundary. Here, the Nuţasca- completely closing the median valley. At this wear Ruseni Tuff cannot be observed in the outcrops. A stage their enamel walls remain separate, but they basal compact yellow-greenish clay layer of 1.5 m fuse at their bases. Small enamel pillars are pre- thickness is overlain by oblique laminated sands sent inside the median valley. The post-fossette is with channel fill lens-like accumulations made of shallower compared to the transverse valley, with coarse sands and sub-angular mud clasts issued oblong ovate outline. On each side cingulums are by the intra-formational erosion. The vertebrate present: the obliquities of the anterior and poste- remains were collected from the lens-like deposit, rior ones are specific for hypsodont teeth. On la- from its basal lag. The teeth and bone fragments bial and palatal sides the cingulums are weak, 186 Codrea, V.A. et al. Figure 1. Location of Pogana locality Figure 2. Lithostratigraphic log of the (Vaslui District) on the geological map. fluvial deposits at Pogana. Figure 3. Chilotherium sp., Pogana, early Late Miocene: 1. – left M2 ; 2. – right p4 ; occlusal views. completely missing at the opening of the median However, the presence of a lingual cingulum is valley. obvious. On the labial side such a cingulum is The lower premolar preserves only the crown, missing. the roots being broken, pre-burial. The tooth is ex- tremely worn on both trigonid and talonid prisms, exposing rectangular outline. Strong mesial and Comparison and discussion distal pressure marks are present, on both sides the enamel being completely removed. The trans- Chilotherium representatives are extremely rare re- verse valleys are extremely reduced: only a small ported in Romania. All the specimens mentioned vestigial area is documenting the anterior one. until now are originating exclusively from areas Early Late Miocene Chilotherium (Perissodactyla, Mammalia) from Pogana (Scythian Platform) 187 located outside the Eastern Carpathians, in Moldo- compared either to C.