The sudden appearance of animals in the fossil record has exercised minds as far back as Cuvier in 1812 [1], and ever since around the time of Steven Stanley's ‘cropping’ hypothesis [2], it has become customary to call this event the ‘Cambrian explosion’. We now date the first definite animal fossils in the record to around 540 million years ago (mya), and by about 515 mya exceptionally preserved biota such as that from Chengjiang followed by the slightly younger Burgess Shale reveal that a wide range of animal taxa with different life-styles had evolved. The implication of the ‘Cambrian explosion’ tag is thus that the fossil record is telling us something real about the speed and nature of the evolutionary events that we can dimly perceive behind it. However, there has always been an alternative view, namely that the oldest fossil record of animals should not be read literally, and instead is the product of a long period of cryptic evolution — in other words, that the first animal fossils post-dated the first animals by some considerable time.