Conventional geology assumes that different rock layers represent different periods of time. Paleontologists assess the age of fossilized creatures by the rock layers in which they are found. So, a fossil found in a lower rock layer is considered to have lived in a much earlier time than one found in a higher ("younger") stratum.

Interesting markings were recently found on a rock in Newfoundland. A study concluded that they were trails left by seafloor-dwelling animals around 565 million years ago. But such a find is difficult to reconcile with the evolutionary teaching that muscles, and therefore animal locomotion, did not evolve until much later.

Fossils from South China are being touted as the first animals to have evolved on the planet. A recently-published study on these tiny organisms, however, presents a fresh evolutionary puzzle. Although the common assumption is that the “first animals” emerged from the ocean, the Chinese Doushantuo Formation looks like it came from lake deposits.