Master of Science
Dr. Jisuo Jin and Dr. Rong-yu Li
The early Silurian reefs of the Attawapiskat Formation in the Hudson Bay Basin preserved the oldest record of major invasion of the coral-stromatoporoid skeletal reefs by brachiopods and other marine shelly benthos, providing an excellent opportunity for studying the early evolution, functional morphology, and community organization of the rich and diverse reef-dwelling brachiopods. Biometric and multivariate analysis demonstrate that the reef-dwelling Pentameroides septentrionalis evolved from the level-bottom-dwelling Pentameroides subrectus to develop a larger and more globular shell. The reef-dwelling brachiopods in the paleoequatorial Hudson Bay Basin were more diverse than contemporaneous higher latitude reef-dwelling brachiopod faunas, with ten distinct community associations recognized in the Attawapiskat Formation. The absence or paucity of hurricane-grade storms in the paleoequatorial Hudson Bay Basin is interpreted as a major factor in the evolutionary success of the reef-dwelling brachiopods in the Attawapiskat Formation.
Gushulak, Cale A.C., "First Major Appearance of Brachiopod-Dominated Benthic Shelly Communities in the Reef Ecosystem during the Early Silurian" (2016). Electronic Thesis and Dissertation Repository. 3972.