A forgotten Miocene mastixioid flora of Arjuzanx (Landes, SW France)

Abstract

The mastixioid flora of Arjuzanx is described within respect of foliage and flattened co-occurring carpological material from the collections of the late Jean Huard, housed at the University of Montpellier (France). The leaf assemblage contains 1 fern, 7 gymnosperms and 76 angiosperms. The spectrum includes also new taxa Distylium huardii sp. nov., Bidens inopinata sp. nov., and Styrax burdigalensis sp. nov. and new records of Tsuga schneideriana Kunzmann & Mai, Marcoduria inopinata Weyland, cf. Cissus sosnowskyi Kolakovskii, Gleditsia sp., Leguminocarpon meczekense Andreánszky, Physocarpus sp., cf. Pistacia sp., and Symplocos cf. bzybica Kolakovskii. Vegetation reconstruction according to the IPR-vegetation analysis belongs to a Zonal subtropical Broadleaved Evergreen forest. This vegetation character was also corroborated by intuitive and geoelement approaches. Palaeoclimatic characters derived from the CLAMP and LMA as well as CoA methodologies indicate comparable average climate estimates as follows: MAT 14.5 °C, CMMT 5.5 °C, WMMT 24 °C and MAP 1190 mm. The distribution of the Eastern Asian elements as well as IPRvegetation analysis and palaeoclimate signals indicate close relationship to vegetation formations of the Mixed Mesophytic and Broadleaved Evergreen forests from SE China and adjacent areas. Phytostratigraphically the Arjuzanx flora based on the complex macrofloristic records shows affinity to the Floral Assemblage Düren sensu Mai (1995) of late Middle – early Late Miocene age.