Megaspore Biharisporites Potonié from the Triassic of Nidpur, Madhya Pradesh, India: A New Report

Abstract

The article reports a dispersed megaspore morphotaxon, Biharisporites Potonié for the first time from the Nidpur beds, Madhya Pradesh, India. The megaspores are structurally preserved compressions and reveal the presence of lycopsids in the parent flora, though macrofossil evidence of such plants is almost lacking. The diagnosis of Biharisporites is emended, to include all externally similar cavate spore types, irrespective of whether their inner sac/ nexine/inner body/mesosporium/inner exospore, is pitted/cushioned or unpitted. The megaspores assigned to the genus are represented by two new species, viz., Biharisporites gopalii sp. nov. and B. bosei sp. nov. They are rare, non-lageniculate, trilete megaspores having spinae or coni on both proximal and distal surfaces. Though the early Triassic has traditionally been interpreted as semi-arid, the recovery of carbonaceous debris from the non-coal bearing Nidpur beds suggests a favourable climate for vegetation in the middle Triassic (Anisian-Ladinian) at the time of deposition of plant debris.