The phylogeny of amiids (bowfin fishes) identifies sister group relationships but not how evolutionary changes arise. Recovering the growth series of sister taxa has the potential to uncover the changes in growth that caused evolutionary differences between taxa. Of focus here is Cyclurus fragosus, an amiid that frequented what is now the Canadian and American West during the last million years of the age of dinosaurs. Previous studies of C. fragosus have not covered growth, providing the rationale for this study to fill that gap in our knowledge.

The primary goal of this study was to recover the growth series of C. fragosus from dentaries (tooth-bearing bone of the lower jaw) based on observation of specimens in the collections of the Dinosaur Discovery Museum (Kenosha, WI) and the Burpee Museum of Natural History (Rockford, IL). Secondary goals included the identification of C. fragosus dentaries, culling data from the literature, compiling quantitative and qualitative data, compiling growth characters, and completing statistical analysis of quantitative data. It was hypothesized that growth and maturity will have a positive correlation.

Based on histograms, scatterplots and trees created using the data, there is a positive correlation between the two measures of Cyclurus fragosus dentaries and maturity. Correlation tests of size and growth stage support this conclusion. From this foundation, the next step is to recover the growth series of Amia calva, the closest living relative of C. fragosus.