First Report of a Trilobite in the Carboniferous of Eastern Pontides, NE Turkey

The pre-Mesozoic basement of the Eastern Pontides consists of a Permo-Carboniferous sedimentary sequence including the Çatalçeşme and Hardişi formations. The Çatalçeşme Formation has yielded rich assemblages of fusulinids, corals, gastropods, brachiopods, bryozoans, algae, conodonts and plants. Hitherto trilobites were unknown from this formation; here we report the discovery of a pygidium from a dark grey limestone bed near the top. Trilobites are a minor component of benthic marine communities during the Late Pennsylvanian, and to our knowledge, the discovery of this pygidium constitutes the first report of their occurrence in deposits of this age in Turkey. The morphological characteristics of the specimen, especially the number of axial rings and pleural ribs and the well-defined border (Owens 1983), suggest that it probably belongs to an undescribed species of Ditomopyge Newell, 1931 (Ditomopyginae). It also exhibits a distortion of the posterior part of the axis, and a shortening (right side) or a fusion (left side) of some pleural ribs, which is tentatively interpreted as repaired injuries or the results of a developmental dysfunction.

First Report of a Trilobite in the Carboniferous of Eastern Pontides, NE Turkey

The pre-Mesozoic basement of the Eastern Pontides consists of a Permo-Carboniferous sedimentary sequence including the Çatalçeşme and Hardişi formations. The Çatalçeşme Formation has yielded rich assemblages of fusulinids, corals, gastropods, brachiopods, bryozoans, algae, conodonts and plants. Hitherto trilobites were unknown from this formation; here we report the discovery of a pygidium from a dark grey limestone bed near the top. Trilobites are a minor component of benthic marine communities during the Late Pennsylvanian, and to our knowledge, the discovery of this pygidium constitutes the first report of their occurrence in deposits of this age in Turkey. The morphological characteristics of the specimen, especially the number of axial rings and pleural ribs and the well-defined border (Owens 1983), suggest that it probably belongs to an undescribed species of Ditomopyge Newell, 1931 (Ditomopyginae). It also exhibits a distortion of the posterior part of the axis, and a shortening (right side) or a fusion (left side) of some pleural ribs, which is tentatively interpreted as repaired injuries or the results of a developmental dysfunction.

___

  • Ağar, Ü. 1977. Geology of the Demirözü (Bayburt) and Köse (Kelkit) Region. PhD Th esis, University of İstanbul, İstanbul, Turkey [in Turkish, unpublished].
  • Babcock, L.E. 2007. Role of malformations in elucidating trilobite paleobiology: a historical synthesis. In: Mıkulıc, D.G., Landıng, E. & Kluessendorf, J. (eds), Fabulous Fossils – 300 Years of Worldwide Research on Trilobites, 3–19. New York State Museum Bulletin 507. Th e University of the State New York, the State Education Department, New York.
  • Canutı, P., Marcuccı, M. & Pırını Radrızzanı, C. 1970. Microfacies e microfaune nelle formazioni paleozoiche dell’anticlinale di Hazro (Anatolia sud-orientale, Turchia). Bollettino della Societa Geologica Italiana 89, 21–40.
  • Çapkınoğlu, Ş. 2003. First records of conodonts from the Permo– Carboniferous of Demirözü (Bayburt), Eastern Pontides, NE Turkey. Turkish Journal of Earth Sciences 12, 199–207.
  • Frech, F. 1917. Geologie Kleinasiens im Bereich der Bagdadbahn. Ergebnisse eigener Reisen und paläontologische Untersuchungen. Zeitschrift der deutschen geologischen Gesellschaft 68, 1–325.
  • Hahn, G. & Hahn, R. 1973. Zur Evolution von Linguaphillipsia (Trilobita; Unter-Karbon). Senckenbergiana lethaea 53, 479– 515.
  • Keskin, İ., Korkmaz, S., Gedik, İ., Ateş, M., Gök, L., Küçümen, O. & Erkal, T. 1989. Geology of the Region Around Bayburt. Mineral Research and Exploration Institute of Turkey (MTA) Report no: 8995 [in Turkish, unpublished].
  • Ketin, İ. 1951. Bayburt yöresinin jeolojisi [Geology of Bayburt region]. İstanbul Üniversitesi Fen Fakültesi Mecmuası 16, 113– 127.
  • Lerosey-Aubrıl, R. & Angıolını, L. 2009. Permian trilobites from Antalya Province, Turkey, and enrollment in Late Palaeozoic trilobites. Turkish Journal of Earth Sciences 18, 427–448.
  • Lerosey-Aubrıl, R. & Feıst, R., in press Quantitative approach of diversity and decline in late Palaeozoic trilobites. In: Talent, J.A. (ed), Global Biodiversity, Extinction Intervals and Biogeographic Perturbations Th rough Time. Springer Publishing, MS 27 pp., 6 figures.
  • Mann, U., Korkmaz, S., Boreham, C.J., Hertle, M., Radke, M. & Wılkes, H. 1998. Regional geology, depositional environment and maturity of organic matter of Early to Middle Jurassic coals, coaly shales, shales and claystones from the Eastern Pontides, NE Turkey. International Journal of Coal Geology 37, 257–286.
  • Newell, N.D. 1931. New Schizophoriidae and a trilobite from the Kansas Pennsylvanian. Journal of Paleontology 5, 260–265.
  • Okay, A.I. & Leven, E.J. 1996. Stratigraphy and paleontology of the Upper Palaeozoic sequence in the Pulur (Bayburt) region, Eastern Pontides. Turkish Journal of Earth Sciences 5, 145–155.
  • Okay, A.I. & Şahintürk, Ö. 1997. Geology of the Eastern Pontides. In: Robınson, A.G. (ed), Regional and Petroleum Geology of the Black Sea and Surrounding Region. American Association of Petroleum Geologists Memoir 68, 291–311.
  • Owens, R.M. 1983. A review of Permian trilobite genera. Special Papers in Palaeontology 30, 15–41.
  • Owens, R.M. & Hahn, G. 1993. Biogeography of Carboniferous and Permian trilobites. Geologica et Palaeontologica 27, 165–180.