Classification: Chordata, Heterostraci, Pteraspidomorphes, Psammosteidae.
Species: D. gemuendenensis (type).
Size: Up to 30 centimetres long.
Known locations: Germany - Hunsrueck Slate Formation.
Time period: Emsian of the Devonian.
Fossil representation: At least two individuals.
Drepanaspis was a fairly flat jawless fish that probably swam close to the sea floor rather than in open water. Drepanaspis is quite unusual in that the mouth faced upwards instead of down like in most other heterostracan fish. The eyes of eterostracans are also set wide apart on either side of the mouth which meant that eterostracans had an exceptionally wide field of view. This may have been to spot for potential predators, or alternatively, been used to identify food or prey sinking down to the sea floor so that an individual could then manoeuvre itself to catch the falling morsel in its upturned mouth.
- Algen und Psilophyten aus dem Unterdevon von Alken an der Mosel, R. Kraeusel and H. Weyland. 1962.
- Pflanzen im Hunsrueckschiefer, W. Stuermer and F. Schaarschmidt -1980.