Research Training Program

Stephanie Fuentes
SUNY Geneseo
Geneseo, New York

Douglas H. Erwin, Ph.D.
Supervising Scientist
Department of Paleobiology

"The RTP is an ideal experience for an aspiring scientist."

Based on statistical analysis of the occurrence of the Ediacaran fauna in time and space, these fossils exhibit patterns in body plan with some respect to time rather than geography. The Ediacaran fauna consists of soft-bodied impressions of variable size and shape typically occurring in shallow marine deposits. The fossils range from about 600 to 543 million years ago and have been found worldwide with particularly abundant assemblages in northern Russia, southern Namibia, and southern Australia. The purpose of this research is to recognize trends in the spacial and temporal occurrence of Ediacaran fossils with the goal of gaining a better understanding of Ediacaran patterns of evolution and radiation. The study of primitive life on Earth may be applicable to the search for life on other planets. Data was collected in a literature review of 100 genera from forty geographic localities and thirty-one stratigraphic formations. The resulting data matrix was divided into three sets: one specifying single formations at each locality, a second grouping all formations at each locality, and a third listing each formation regardless of geographic setting. Data was analyzed with Hierarchical Cluster Analysis (HCA) and Multi-Dimensional Scaling (MDS). HCA provides distinct groupings, or clusters, of data entries, while MDS allows the analyst to decide which groupings are appropriate and on what basis they vary. The guidance of HCA and freedom of MDS have proven to be very successful in ecological studies. Unexpectedly, the Ediacaran fauna shows no trends in geographic locality. There are several cosmopolitan genera resulting in diverse assemblages. The main factor on which these assemblages differ is not space or time, but rather, morphology. Within these confines there is some evidence of temporal distinction with increasing complexity. Discrepancies among chemically correlated formations and unexpected patterns in morphologic occurrence suggest strong variations in ecologic, and therefore, preservational, circumstances between localities.