Edestus

Edestus is an extinct genus of cartilaginous fish belonging to the order Eugeneodontiformes. These ancient sharks are known from fossilized teeth and jaws, primarily from the Carboniferous and Permian periods. The most distinctive feature of Edestus is its bizarre dentition. Instead of having multiple rows of teeth that are continuously replaced, Edestus possessed a unique jaw structure where teeth grew in a continuous series, forming a scissor-like apparatus. The upper jaw typically featured a pair of elongated, symphyseal teeth that protruded downwards, while the lower jaw held a series of smaller, more numerous teeth.

The exact function of this unusual jaw structure is still debated among paleontologists. Theories suggest it may have been used for slicing through soft-bodied prey, such as ammonoids or other marine invertebrates. The large, forward-projecting teeth could have acted like shears or rakes. Edestus fossils are found in marine deposits across various continents, indicating a widespread distribution during its time. Despite its strange appearance, Edestus represents an important evolutionary branch of early shark-like fishes, showcasing the diverse adaptations that arose in the Paleozoic seas. The genus is known from several species, distinguished mainly by variations in the size and shape of their teeth.