Gymnosperm Foliage from the Lower Jurassic of Jirande Area, Western Alborz Mountain, North Iran

Abstract

This paper describes five gymnospermous macro-remains, including bennettitalean (Otozamites furoni), coniferalean (Pityophyllum longifolium and Stachyotaxus septentrionalis), ginkgoalean (Sphenobaiera gyron), and czekanowskialean (Phoenicopsis speciosa) leaves, from the Jirandeh area in the western Alborz, Iran. Materials were collected from a Lower Jurassic coal-bearing horizon within the Shemshak Group in the Jirande locality. The morphological characters of encountered gymnospermous remains, together with their palaeogeographical distribution and stratigraphical occurrences, are discussed herein. The species Sphenobaiera gyron is recorded here for the first time from Asia. Pityophyllum longifolium and Stachyotaxus septentrionalis are described for the first time in Iran. This is also the first report of Phoenicopsis speciosa from the western Alborz region. The upland environment under a subtropical to warm-temperate climate is suggested for the Lower Jurassic deposits in the Jirande area based on the occurrence of the encountered gymnospermous taxa.