Ediacara fossil assemblage in the upper Vindhyans of Central India and its significance

Wide biogeography and ecological uniformity qualify the Vindhyan fossils as biostratigraphically significant group that fixes the age of the Lakheri-Sirbu segment at latest Neoproterozoic, helps in intercontinental correlation of the Bhander Group and focuses supra-Sirbu sequence as potential bearer of early Cambrian organic signatures. Predominance of forms representing Cycloza, an archaic group having monaxonic heteropolar symmetry of infinitely high order (e.g. Cyclomedusa) in F1 and Inordoza having high order radial symmetry (e.g. Hiemalora) and Trilobozoa, an advanced group with fixed order radial symmetry (e.g. Tribachidium) in F2 is consistent with the early evolutionary trend of coelenterates. Association of bilateral arthropod Spriggina, commonly thought to be ancestral to Arthropoda and Annelida now separated by huge phylogenic gulf, with possible discoid sponge of high-level organization and coelenterates suggests phyletic diversity of the Vindhyan Ediacara.