BOTA2000 Lecture Notes - Lecture 3: Cordaites, Glossopteridales, Archaeopteris
Document Summary
Appreciate that determining a true phylogeny of gymnosperms is an active area of research. Understand what distinguishes groups of extant gymnosperms from one another: know the significance of seeds and their evolutionary importance, learn the features of typical conifer pollen and seed strobili and how they differ. Appreciate the modifications of pine leaves that adapt them to harsh environments. Heterospory separate female megaspore and male microspore. Female gametophyte retained on mother plant (sporophyte) and enclosed within protective maternal seed coat (collectively the ovule) Ovule has opening designed to receive pollen that does not depend on water for male gamete transfer. Devonian period (350- 385 mya) extinct group (progymnosperms) Carboniferous period became abundant as survived in dryer, colder permian (280 mya) Cordaites - basal gymnosperms with male pollen cones, female seed producing cones. Glossopteris is the largest and best-known genus of the extinct order of seed ferns known as.
