RESTUDY OF AN EDIACARAN MEDUSOID MARSONIA ARTIYANSIS RAGHAV ET AL., 2005, FROM THE JODHPUR SANDSTONE, JODHPUR DISTRICT, WESTERN RAJASTHAN

摘要

A medusoid Marsonia artiyansis Raghav et al. 2005 reported from the Jodhpur Sandstone of Ediacaran age has been restudied for its taxonomic affinity. The present study suggests modification in the diagnosis. The conclusion drawn by Raghav et al. (2005) concerning its affinity with a medusoid of Class Scyphozoa can be accepted on the basis of morphology characterized by a circular disc-shaped structure with smooth to wrinkled margin and mode of preservation in a very shallow water lagoonal setting. The animal must have been planktic with soft body without hard parts. The diameter varies from 0. 5cm to 5. 5cm with mean value as 1. 08 cm, (n=60). In the centre, there is a circular mark. Much of the central part is uneven but marked by four arms and a few bead-like structures. The major variation in morphology is possibly due to taphonomy and load-effect of overlying sediments.