MioceneCupressinoxylonfrom Gökçeada (Imbros), Turkey withProtophytobiacambium mining and the study of ecological signals of wood anatomy

Abstract

PremiseThe recognition of the Miocene Climate Optimum (MCO) in terrestrial palaeoenvironments of the Eastern Mediterranean is restricted to Lesbos and Lemnos Islands, Greece. This area is significant for its wood microfossils. A recently-discovered fossil wood assemblage from Gökçeada (Imbros) Island, Turkey, including tree species similar to the Greek findings, is thought to have an early Miocene age. Here, we revise the age of the latter plant fossiliferous locality, re-evaluate the area for the study of MCO for the terrestrial palaeoecosystems of the Eastern Mediterranean and the nomenclature errors referring to the occurrence of fossil wood. We present the plant–insect–environment interactions using detailed anatomical descriptions, of an extinct conifer and its extinct cambium miner feeding traces observed in its secondary xylem.MethodsThree thin sections were prepared with standard palaeoxylotomical techniques from a small section of the silicified wood; the sections were observed under a light microscope. The anatomy of the conifer and its damage patterns were compared with those of extant and fossil Cupressaceae and Agromyzidae, respectively.Pivotal resultsThe common anatomical features of the studied wood specimen andHesperocyparis macrocarpa(Hartw.) Bartel and a shared characteristic (the number of the cross-field pits – a feature we consider of diagnostic value) withXanthocyparis vietnamensisFarjon & T.H. Nguyên led to its assignment to theHesperocyparis–Xanthocyparis–Callitropsisclade. The detailed study of the wound scars and anatomical abnormalities, the anatomical–environmental associations, and structural–functional reactions follow the identification of the wood’s anatomysensuCarlquist providing decisive results.ConclusionsBased on the distinctive characteristics presented, we identify our macrofossil asCupressinoxylon matromnenseGrambast, a stem or an extinct lineage of theHesperocyparis–Xanthocyparis vietnamensis–Callitropsis nootkatensisclade with feeding traces of the fossil cambium miner of the genusProtophytobiaSüss (Diptera: Agromyzidae), and anatomical damage and reaction tissue on adventitious shoots. The use of Protopinaceae andPinoxylonF. H. Knowlton from the eastern Mediterranean are re–evaluated and corrections are provided. The age of the studied plant fossiliferous locality in Gökçeada is revised as middle Miocene, allowing the proposal of an eastern Mediterranean MCO hotspot, including Lesbos, Lemnos, and Gökçeada (Imbros) Islands.