Falcatus; pronounced fal-CAT-us
Shallow seas of North America
Early Carboniferous (350-320 million years ago)
Size and Weight:
About one feet long and one pound
Small aquatic animals
Small size; disproportionately large eyes
A close relative of Stethacanthus, which lived a few million years earlier, the tiny prehistoric shark Falcatus is known from numerous fossil remains from Missouri, dating from the Carboniferous period. Besides its small size, this early shark was distinguished by its large eyes (the better for hunting prey deep underwater) and symmetrical tail, which hints that it was an accomplished swimmer. Also, the abundant fossil evidence has revealed striking evidence of sexual dimorphism--Falcatus males had narrow, sickle-shaped spines jutting out of the tops of their heads, which presumably attracted females for mating purposes.