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Researchers in this study also revisited an analysis of fossilized placoid scales, or tiny tooth-like scales that cover sharks, from the megalodon.

The fossils discovered include 134 teeth, 61 vertebrae, 23 placoid scales and fragments of calcified cartilage, researchers said in a statement.

As to whether they represent the remnant of a once present system of epidermal scales, which may have preceded the coating of placoid elements in the evolution of the vertebrate, there is no evidence.

The remains of fish are as yet confined to the upper part of the Silurian series; but some of these belong to placoid fish, which occupy a high grade in the scale of organization.

A singular species, rare, but easily recognized by its peculiar, placoid scales, large and firmly embedded in the peridial wall.