Scientists move closer to linking embryos of the Earth's first animals to adult form

Abstract

In 1998, Shuhai Xiao and colleagues reported finding thousands of 600-million-year-old embryo microfossils in the Neoproterozoic Doushantuo Formation, a fossil site near Weng'an, South China (Xiao, S., Zhang, Y., and Knoll, A.H., 1998, "Three-dimensional preservation of algae and animal embryos in a Neoproterozoic phosphorite," Nature, v. 391). Within the egg cases they examined at that time, they discovered animals in the first stages of development - from a single cell to only a few dozen cells. "The cellular preservation is amazing," said Xiao, assistant professor of geosciences in the College of Science at Virginia Tech.