Research Training Program

Smithsonian Institution
National Museum of Natural History

PROJECT SUMMARY
1996

Forest J. Gahn
Brigham Young University
Provo, UT
Stephen D. Cairns, Ph.D.
Supervising Scientist
Department of Invertebrate Zoology
"I've always dreamed of coming to the Smithsonian to do research in the Springer Collection, but l never thought it would happen as an undergrad! I'm so grateful for the Research Training Program and all of the beautiful Burlington crinoids it made available to me. Working with Dr. Cairns was great too. He actually turned my head for a few months and got me interested in something else!"

Revision and Phylogenetic Analysis of Notophyllia (Cnidaria: Scleractinia)

ABSTRACT
Notophyllia is a small (about the size of a dime) coral that was first found as a fossil in 15 million year old clay deposit in Victoria, Australia. Today, this coral is found at depths of 120-1,500 feet, and is found only in the cool ocean waters off the coast of southern Australia. There are four fossil and four recent representatives of Notophyllia known today. All of them are described in this paper, one of them for the first time. The purpose of this paper is not only to describe the eight species of Notophyllia, but to understand phylogenetic relationships between them. Phylogenetics is the study of evolutionary relationships between organisms. There are several computer programs that are used to test these relationships. The two that were used here are called PAUP and MacClade. They first require that several skeletal and structural parts of many specimens be measured. After this necessary information is gathered, an outgroup must be chosen. An outgroup is an organism that is very closely related to the organism under study. In this analysis of Notophyllia, two outgroups were chosen: one genus called Lamellophyllia and another called Endopsammia. The same information had to be gathered about these corals as were for Notophyllia. After all of the important data was accumulated, it was entered into the computer and analyzed. Out of over two million possible "family trees" for Notophyllia, the computer gave only ten. In all ten of the trees, the fossil corals were placed as ancestors to the recent ones. Three of the ten trees showed one or two species of Notophyllia branching off of Endopsammia. It is clear that Notophyllia represents a group of corals that came from a single ancestor, so the other possibilities were excluded, leaving only seven trees. Four of the seven remaining trees showed the development of five-part symmetry, from six-part symmetry, twice in Notophyllia. Symmetry is a very conservative character in corals, so it was concluded with the three trees that five-part symmetry evolved only once. This study helps to better understand the evolution of Notophyllia over the last 15 million years.

This research was supported by a grant from the National Science Foundation Research Experiences for Undergraduates program, Award Number DBI-9531331.

Letter of Gratitude