Original paper

The Rhaeto-Jurassic flora of Iran and Afghanistan. 14. Pterophyta - Leptosporangiatae

Schweitzer, Hans-Joachim; Schweitzer, Ute; van Konijnenburg-van Cittert, Johanna H.A.; van der Burgh, Johan; Ashraf, Rahman Abdul

Abstract

This 14th and final monograph on the Mesozoic plant micro- and macrofossils of Iran and Afghanistan deals with the leptosporangiate ferns. After the introduction, the stratigraphic distribution of more than 200 different plant species in the flora is treated with the aid of a number of tables. The climatic changes accompanying the floristic changes from the middle Norian up to the end of the lower Middle Jurassic are discussed as well in this introduction. During the Mesozoic the central part of Iran with the coal basins of Kerman and Tabas was situated on a different tectonic plate (Iran-plate) than North Iran and Afghanistan (Turan-plate). These plates had collided previously during the late Palaeozoic resulting in the same sedimentation conditions on both plates during the Mesozoic and consequently related floras occurred on both plates. The original idea of Krumsiek (1976), that the collision took place in the Late Tertiary, was contradicted earlier by the palaeobotanical findings of Schweitzer (1978). A third chapter is dedicated to the great botanical and phylogenetic importance of the floras from the Middle Orient and the fourth section is a systematic study of the flora. Especially significant are the new fructifications of Nilssoniales, Bennettitales, Ginkgophytes (including the Czekanowskiales) and conifers which bring new insights in our knowledge of these plants.

Keywords

leptosporangiate fernsNilssonialesBennettitalesGinkgophytesconifersAlborz KermanIranAghanistan