Résumé
The Glossopteridales are an emblematic extinct group of seed plants that dominated most of the floras of the supercontinent Gondwana during the Permian period, 298-251 million years ago. Glossopteridales occupied a wide range of habitats and occurred from midlatitudes to the southern polar regions (> 75°S) where they formed highly productive forests under the late Permian greenhouse climate 1,2 . This talk will review some of the information on the biology of Glossopteridales accumulated during the last 15 years of work on permineralized material from late Permian deposits of the Central Transantarctic Mountains, Antarctica. Evidence indicates that these plants could produce a thick insulating bark -at least at the base of the tree 3 , had the ability to produce epicormic shoots 4 , formed endomycorrhizal associations with glomeromycetes 5 , and may have had various leaf habits (deciduous and evergreen, 6 ). These traits suggest that Glossopteridales could tolerate stressful conditions and colonize a variety of environments. In addition, there are indications of self-facilitation within the group, based on the structure of their rooting systems and evidence of "nurse log" behavior 7,8 . We will also demonstrate that some new specimens show the production of stem-like lateral axes from young glossopterid roots and these are interpreted as evidence of root suckering. This new discovery complements reports of the presence of a lignotuber and/or of basal suckering in some Glossopteridales from Australia 9 . This is currently the oldest report of root suckering in a fossil plant and it provides additional evidence in favor of high resilience potential among glossopterids.