Fish Pectoral Musculatures

The history of how fish became tetrapod’s is not crystal clear yet, however scientists have used Polypterus as an example of a transitional fossil. According to the article Polypterus and the evolution of fish pectoral musculature, Polypterus are the best option for laboratory work with

the evolution of pectoral musculature over the fin-limb transition. The musculature of Latimeria is likely a better model, but their completely pelagic lifestyle and endangered status rules them out for laboratory work.