Cycas is considered as a living fossil because it is the only living species in the family Cycadaceae. All other species of this family are now extinct. This plant is often considered as the plant of the Old World; which means it is found only at those places which can be associated with some of the oldest rocks in the world. Due to these reasons; it is called as the ‘relic of the past’. Moreover, Cycas shows more resemblance with Pteridophytes than Gymnosperms. This shows phylogenetic relationship between Pteridophytes and Gymnosperms. Some of the characters of Cycas which indicate towards this are as follows: 
(a) Seeds are shed when the embryo is still mature. In other gymnosperms; seeds are shed only when the embryo is mature.
(b) The megasporophyllus appears like leaf.
(c) In spite of the presence of pollen tubes, male gametes are flagellate.
(d) Leaf base is persistent.
(e) Circinate ptysix; which is similar as in Pteridophytes.