Fossils that document the first 85 percent of the history of life are predominantly microscopic. Only in the last 544 million years have the remains of large animals and, later, plants become abundant, leading geologists to christen this interval the Phanerozoic Eon -- the age of visible life. The key event that connects these strikingly different eras is the evolution of complex multicellularity. Multicellular organisms arose at least six times in animals, fungi, and several groups of algae. A handful of fossils suggest that multicellular red, green, and stramenopile (brown and related) algae existed a billion years ago. Multicellularity may have arisen comparably early in tiny ancestral animals, but until now any pre-Ediacaran animal record was thought to be inaccessible to paleontologists.
A remarkable fossil deposit is now shedding unprecedented new light on the early diversification of multicellular organisms. Phosphorites of the 600-550 million year old Doushantuo Formation, China, contain three-dimensionally preserved fossils that record of early life yet discovered in Precambrian rocks; indeed, they must rank among the most important fossil deposits of any age.
A two-year research project is proposed to investigate the systematic paleontology and paleobiology of multicellular fossils in the Doushantuo phosphorites. In collaboration with Professor Zhang Yun of Beijing University, the research team will collect large volumes of material from localities that our previous research has shown to be fossiliferous. New, potentially productive4 localities will also be sampled in the field. Samples will be prepared in the laboratory and studied by light and electron microscopy. It is anticipated that this research will provide a new empirical, paleontological framework for understanding a major transition in the history of life.
