a1 Área y Museo de Paleontología, Departamento de Ciencias de la Tierra, Facultad de Ciencias, Universidad de Zaragoza, c/Pedro Cerbuna, 12, E-50009, Zaragoza, Spain
a2 Palaeontological Institute, Russian Academy of Sciences, ul. Profsoyuznaya 123, Moscow 117997, Russia
We describe the first occurrence of the problematic fossil Gaojiashania outside China, in the Ediacaran Yudoma Group of the Siberian Platform. In both areas, Gaojiashania characterizes the lower upper Ediacaran strata and precedes the appearance of Cloudina and other skeletal fossils, which highlights its significance for the Ediacaran subdivision and correlation. Features of this fossil such as indeterminate length, the absence of a distinct growth pattern, and self-avoiding behaviour indicate its trace fossil origin but do not necessarily imply metazoan affinities for its producers. Several organisms including stem-group social amoebozoans and unicellular protists may have been Proterozoic trace fossil producers.
(Received December 09 2008)
(Accepted April 27 2009)
(Online publication July 02 2009)