THE FOSSIL HISTORY OF GINKGO LINNAEUS
D. K. CHAUHAN *
Department of Botany, University of Allahabad, Allahabad -211 002, India.
S. P. TIWARI *
Department of Botany, University of Allahabad, Allahabad -211 002, India.
*Author to whom correspondence should be addressed.
Abstract
The Ginkgophytes are an ancient group of plants which are believed to have existed during the Early Permian and are represented today by a single monotypic genus Ginkgo biloba L. Although, there is a rich fossil record of Ginkgo and Ginkgo like leaves but their reproductive structures are relatively rare and this has made our ability to trace the evolutionary history of Ginkgo, a bit difficult. The cladistic analysis suggest that Ginkgoales is a monophyletic group that includes Trichopitys, Polyspermophyllum, Karkenia, Toretzia, Umaltolepis, Yimaia, Grenanaand Ginkgo.
Keywords: Cenozoic, Cladistic, Ginkgophytes,, Mesozoic, Monophyletic, Palaeozoic