Rhenanida

Gemuendina stuertzi from the Lower Devonian Hunsrück ( Hunsrückschiefer ). Plaster cast of the back side of the Museum of Natural History, Berlin

• North America, Bolivia, Germany

The Rhenanida ( Rhenaniformes, Asterosteidae ) are a group of extinct placoderms, fishy, heavily armored vertebrates from the Devonian. They were ground-dwelling marine animals.

Features

The Rhenanida were flattened roche -like. In contrast to all other Placodermen whose head and body was armored by large bony plates that Rhenanida had an armor of a mosaic of small bony plates. They had on each side only one gill opening. The mouth opening was at the head base. The Rhenanida reached 20 to 30 centimeters in length.

There are only three well-known genera, Bolivosteus, Gemuendina and Jagorina.