Cambrian

The Cambrian Explosion (the abrupt appearance of animal phyla in the earliest fossil layers bearing multicellular body plans) remains unmuffled. Known by Darwin as a problem for his theory, it has become more problematic to his followers over time. There are now many more Cambrian fossils than Darwin knew of, and they continue the pattern: sudden appearance of complex animals, complete with legs, digestive systems, eyes, and nervous systems. Discoveries of Precambrian fossils have not helped: the ones that are more than microbial appear to be mere colonies of cells with no relationship to animals. Here are more discoveries that fit this pattern.