Currently, scientists have done a research and came to know that the first animal phyla emerged in rapid succession -- prior to the global Ice Age that set in around 700 million years ago. The fossil record disclosed that almost all of the animal phyla known today had come into existence by the beginning of the Cambrian Period some 540 million years ago.
The previously known animal fossils already displayed complex morphologies. The earliest discovery implies that animals must have originated long before the onset of the Cambrian. However, taxonomically transferable fossils that can be confidently dated to pre-Cambrian times are very unusual. The biologists need reliable dating information for the most ancient animal subgroups and to determine what the root of their family tree looked like.
Dr. Martin Dohrmann stated that and Professor Gert Wörheide stated that the sponges, cnidarians, comb jellies and placozoans are few known ancient animal subgroups. Additionally, the research took place at the Department of Earth and Environmental Sciences at Ludwig-Maximilians-Universitaet (LMU) in
By: Priyanka Negi