DINICHTHYS (“δεινός” – terrible, “ἰχθύς” – fish) at that time was the largest and most powerful marine predator. Its length reached 8-9 m. The jaws of this armoured fish, similar to the bucket of an excavator, were serrated arcs of hard dentin. The head plate had holes for the eyes. The length of the head shield of this fish exceeded 1 m.
Some of the armoured fishes had fin-like organs, also covered with bone shields, on the boundary of the head and body. Most likely, these organs did not serve for swimming, but for grasping prey, which is confirmed by the presence of serrated edges facing each other.
Skull of the armoured fish Dinichthys terelli in the museum's exhibition
Dinichthys reconstruction
Heterosteus is one of the largest armoured fish. Its length reached 6 m. Its large flattened head shield, consisting of bone plates adjacent to each other, was oval in shape and could be more than a meter in length. Much smaller bony plates also covered the body of the armoured fish.
Heterosteus had a powerful long tail and developed muscles.
It did not have an internal bone skeleton, but the shell supported the body of the fish, and the bone plates that covered the body protected it from predators.
Heterosteus lived in shallow warm water bodies, and probably fed on plankton. The fossilized remains of these armoured fish were found in the modern Baltic states, Germany, Greenland, Svalbard.
Reconstruction of Heterosteus asmussi