The phrase "animal phyla" refers to different groups or categories in which animals are classified based on their shared characteristics or traits. Full definition
It centers on one of the most remarkable events in that history, the relatively rapid emergence of animal phyla in the Cambrian. (science.sciencemag.org)
According to Strausfeld, confirmation of this shared ground pattern in the vertebrate hippocampus would suggest that it originated from a very ancient common ancestor likely to have lived about 600 million years ago just before the Cambrian explosion, a relatively short period when most major animal phyla emerged. (sciencedaily.com)
Meyer holds that the emergence of animal phyla in the Cambrian demonstrates the existence of an intelligent designer. (science.sciencemag.org)