The division of gymnosperms that includes only the extant Ginkgo biloba (maidenhair tree) and its extinct relatives. The first undoubted maidenhairs occur in Triassic rocks, and in the subsequent Jurassic Period their distribution was practically worldwide. The surviving species is restricted (in the wild) to China, and its leaves are strikingly similar to fossil Ginkgo leaves from the Triassic. The restricted geographical range, the unchanged appearance of the leaves, and the motile male sperms (otherwise known only in living seed plants in the Cycadales) have together led to the maidenhair being referred to as a ‘living fossil’.
Subjects: Plant Sciences and Forestry.