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. Melvius thomasi is an amiid from late Cretaceous rocks of western North America; it lived alongside the amiid Cyclurus fragosus. There are very few growth studies of M. thomasi due to its incomplete fossil record; the goal of this study is to help fill this gap in knowledge. 

The primary goal of this study was to recover the growth series of M. thomasi using cladistic analysis based on 6 specimens; data were from dentaries in the collections of the Dinosaur Discovery Museum (Kenosha, WI). Secondary goals included the identification of M. thomasi dentaries, culling data from the literature, compiling quantitative and qualitative data, and compiling growth characters. It was hypothesized that growth and maturity will have a positive correlation.