The oldest cnidaria in the ecosystem of thr Volyno-Podilsky sedimentation basin on the border of the Proterozoic and Paleozoic

The author found many fossils in the Upper Ediacaran deposits of Podilla, which have not been systematically described. The morphology and paleoecology of some of these fossilized remains indicate their probable belonging to the oldest pelagic jellyfish (Medusozoa), polyps of the group of sea anemones (Anthozoa), and ancestors of Sphenothallus (Conulariida), extinct at the end of the Paleozoic. Such a complex of biotic remains in Ediacaran sediments was discovered for the first time in world practice. The absence of similar findings in other regions gives reason to consider the Volyn-Podilskyi sedimentation basin of the Ediacaran period as the most crucial center of speciation (origin and evolution) of the main groups of Cnidaria. For the first time in the history of paleontological research, a monotopic series of fossilized remains was collected, which illustrate the stages of metamorphosis of the oldest organisms, close to the stages of ontogenesis of modern pelagic Scyphozoa (Medusozoa). Based on the fact that modern jellyfish and sea anemones are predators and there is no evidence that they had ancestors with a different way of life, and based on published data of molecular studies of the genome of various groups of Cnidaria, it is hypothesized that the oldest organisms were found in the Volyn-Podilsky sedimentary basin ecosystem of the Ediacaran period representatives of predation. The results contradict the common point of view about the absence of predation in the Neoproterozoic ecosystem.