Yezi Yang
Advisor: Katherine Marenco
Geology Department

Ordovician Receptaculitids from Western Utah: Investigating the Morphology and Paleobiology of an Enigmatic Fossil Group

Receptaculitids are enigmatic organisms that lived from the Early Ordovician through Permian Periods (488-250 million years ago), and are considered important components of Early Paleozoic shallow-water reefs along with sponges and microbial communities. Their body shapes vary widely but in general they share a distinctive helicospiral skeletal structure. Researchers have recognized similarities between receptaculitids and both sponges and algae, but currently there is no consensus on how this fossil group should be classified.

The goal of my research is to investigate the morphology and paleobiology of receptaculitids collected from the Early Ordovician Fillmore Formation of western Utah. Most of the receptaculitid specimens that I will be working with are incomplete and conical or cylindrical in shape, but one fossil is complete and goblet-shaped. I will make thin sections both parallel and perpendicular to the body axis of several of the receptaculitid specimens and polish the surfaces of other specimens in order to reconstruct the three-dimensional skeletal morphology and microstructure of these organisms. Based on my data and the existing literature, I will interpret the physiology and phylogenetic placement of these Fillmore Formation receptaculitids and explore their role within Early Ordovician reef habitats.