Heterostraci
Fish
Lower Devonian (Pridolian)
Dniester Formation
Zalishchyky, Podolia, Ukraine

55mm shield on 94mm slab.

This is a shield of an unidentified armored jawless fish of the extinct Subclass, Heterostraci, aka the heterostracans.  The shield is composed of bone and dentine, protecting the head and part of the body. Usually, all that is found of these fishes are isolated shields. Heterostracans were very diverse (over 300 known species) during the Silurian but they died out by the end of the Devonian.

This specimen is for the fish collector looking for an affordable example of one of the early Paleozoic jawless fish groups. It’s also for the general vertebrate collector looking for something representing the stage in vertebrate evolution not long after the development of a mineralized skeleton.

Affordable specimen of a truly ancient fish in matrix.