(Bernard Price Institute for Palaeontological Research, 1997) Brain, C. K.
The purpose of this review is to draw attention to the contribution that Nama sediments and fossils
have made, and potentially can make, to the ongoing debate about metazoan origins. Two important
features of this debate concern the nature and systematic position of the late Proterozoic "Ediacaran"
fauna as well as the reasons for the sudden appearance in the fossil record of representatives of almost
all known animal phyla, during the Early-Middle Cambrian radiation. An additional vexing question
is the reason for the apparent absence of preserved representatives of ancestral metazoan lineages in
Proterozoic sediments, despite the fact that molecular evidence shows that such lineages had a long
his tory, prior to Cambrian times. Nama fossils and their enclosing sediments have made crucial
contributions to this debate and will surely continue to do so in the future.