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Living Fossils T HE cycads are a group of very primitive plants that are very similar in appearance to palms although they are not related to it. Like Cockroaches, cycads too are called “living fossils,” because they have persisted almost unchanged down the ages. As a group, cycads reached their evolutionary pinnacle about 200 million years ago and, since then, their population has been on a downswing. Fossil cycads aged about 240 million years ago share many characteristics with the cycads alive today. Just like the Wollemi Pine, cycads too may well have provided food for herbivorous dinosaurs and fossilized cycads are frequently found in the same rocks as dinosaur bones. The Jurassic Period is sometimes called the “Age of cycads” because they were so common then. Living cycads are represented by about 300 or so species and about a dozen or less genera. They usually grow in tropical and subtropical regions although a few are found in temperate regions. Cycads have a central trunk topped by a whorl of leaves, usually without any side branches. Like palm leaves, cycad leaves too have a central stalk flanked by rows of narrow leaflets on both sides. Cycads are gymnosperms, which means “naked seed” and as such, they bear cones, but never a true flower. Male and female cones are borne on separate plants. All species of cycads are endangered. According to the IUCN—World Conservation Union’s Cycad Specialist Group—cycads represent one of the most threatened plant groups in the world. Dangers to living population are largely due to habitat destruction and over-collection of specimens; and so these plants are covered by the import/export restrictions of the Convention on International Trade in Endangered Species (CITES). That even fossilized cycads can go “extinct” because of overzealous collection is exemplified by what happened at the Cycad National Monument, USA. In 1892, F. H. Cole was exploring government owned land near Minnekahta, USA when he discovered one of the world’s greatest surface concentrations of fossilized cycads—actually an “entire fossil forest of cycads.” Cole sent photographs of the fossil cycads to geologist Professor Henry Newton of the Smithsonian Institution. In 1893, Professor Thomas MacBride published the first description of the site. Paleobotanist George Reber Wieland at Yale University was concerned about the Cycads Untouched by Time vulnerability to plunder and used the Homestead Act to gain ownership of 320 acres containing the fossils. In 1922 he returned the land to the government, on condition that a national monument was created there. This site was proclaimed a national monument on 21 October 1922. The US President declared that the national monument was being established because there are: “..... rich Mesozoic deposits of fossil cycads and other characteristic examples of paleobotany, which are of great scientific interest and value....” Unfortunately, even before the Fossil Cycad National Monument formally came into existence, illegal collectors managed to carry away all the fossil cycads that had made the site worthy of national park status. On September 1, 1957, the United States Congress voted to de-authorize the Fossil Cycad National Monument. (More details are available at (http:// w w w. n a t u r e . n p s . g o v / G e o l o g y / paleontology/pub/grd3_3/focy1.htm ) This was not the only loss that the fossil cycads faced. Prior to 1988, the state fossil of South Dakota, USA, was the cycad. When illegal collecting destroyed the Fossil Cycad National Monument, both the park and the cycad lost their official status. However, scientists seem to have learnt their lesson well. Today there are Cycad Societies dedicated to the conservation of cycads across the world. Let us hope that these ancient plants that have survived the ravages of time will triumph over human exploitation as well. Dr Sukanya Datta Scientist NISCAIR posted to Director General's Technical Cell, CSIR HQ Email: [email protected] SCIENCE REPORTER, June 2010 55