''Logania'' is a genus of jawless fish which lived during the

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozo ...

and Early Devonian period. Like other thelodonts, the body was covered in

denticle A denticle is any small tooth-like or bristle-like structure. "Denticle" may refer to: * Denticle (tooth feature), serrations on the teeth of dinosaurs, lizards, sharks, and mammals * Dermal denticles or placoid scales, in cartilaginous fishes * ...

s, which in ''Logania'' were interlocking and stud-like.

References

Thelodonti genera Paleozoic jawless fish Devonian extinctions Silurian first appearances {{Paleo-jawless-fish-stub