Dwarfism and Lilliput Effect: A Study on the Glossopteris from the Late Permian and Early Triassic of India

The 'Lilliput effect' represents the phenomenon whereby there is a pronounced reduction in the size of biota associated with the aftermath of mass extinction. This fact has been supported by the evidence of dwarfism both in invertebrates and vertebrates recorded after the end-Permian mass extinction event. The extinct genus Glossopteris belonging to seed ferns Glossopteridales is one of the best known fossil taxon that flourished during the Permian and continued its existence till Triassic. In contrast to the Permian, the Triassic was a time when greenhouse conditions with an increased temperature and widespread aridity prevailed as evidenced by the global dataset. The new set of environmental conditions in the Triassic posed a major challenge for the existing Glossopteris lineage, whereby the smaller forms (dwarfs) with reduced leaf surface area continued and sustained. The present study from different late Permian and early Triassic formations of India is aimed at unravelling the changes in morphological traits of seven species of Glossopteris leaves whose existence continued surpassing the Permian-Triassic mass extinction event.