The Cambrian explosion
02 / 07 / 2015, Economist Science and Technology
Modern lobopodians are rarely seen forest dwellers called velvet worms. Their ancient relatives, though, were pioneers of the Cambrian explosion, a time when Earth experienced an unprecedented surge in biodiversity. As they report in the Proceedings of the National Academy of Sciences, Zhang Xiguang of Yunnan University, in China, and his colleagues have found a previously unknown species (pictured), some 520m years old, in rocks from Yunnan province. Collinsium ciliosum, as they dub it, could grow to be more than 8cm long, was eyeless and had frontal appendages that were developed into sieving baskets, to filter food from the ocean floor. A tasty morsel, then, for the numerous predators which the Cambrian explosion generated. As a consequence the creature was, in Dr Zhang’s phrase, “superarmoured”, with five spines of varying length protecting each of the 14 rear segments of its hardened exterior.