Prehistoric Models: Placoderms
Placoderms are a class of armored fish that first appeared in the fossil record at the end of the Silurian period about 430 million years ago. But a majority of Placiderms lived in the Devonian period and were extinct by the beggining of the Carboniferous Period.
Kingdom: Animalia – Phylum: Chordata – Subphylum: Vertebrata – Infraphylum: Gnathostomata – Class: Placodermi
(Placoderms “armored fish”)

Genus: Groenlandaspis “Greenland shield”.
Pronounced: Green-land-as-piss.
Named By: Heintz - 1932.
Species: G. mirabilis (type). G. antarctica, G. disjectus, G. pennsylvanica, G. potyi, G. riniensis, G. seni, G. theroni, G. thorezi.
Classification: Class: Placodermi, – Order: Arthrodira, – Family: Groenlandaspidae.
Locations: Global
Time period: Late or Upper Devonian.
Size: Up to 9 meters long.
Diet: Carnivore

Genus: Dunkleosteus ”Dunkle’s bone”.
Pronounced: Dun-kel-os-tee-us.
Named By: Lehman - 1956.
Species: D. terrelli (type), D. amblydoratus, D. marsaisi, D. raveri.
Classification: Class: Placodermi, – Order: Arthrodira, – Family: Dunkleosteidae.
Locations: Canada. USA. Europe. Morocco.
Time period: Late Devonian (Frasnian to Famennian).
Size: Up to 9 meters long.
Diet: Carnivore/Piscivore.

Genus: Dunkleosteus ”Dunkle’s bone”.
Pronounced: Dun-kel-os-tee-us.
Named By: Lehman - 1956.
Species: D. terrelli (type), D. amblydoratus, D. marsaisi, D. raveri.
Classification: Class: Placodermi, – Order: Arthrodira, – Family: Dunkleosteidae.
Locations: Canada. USA. Europe. Morocco.
Time period: Late Devonian (Fransian to Famennian).
Size: Up to 9 meters long.
Diet: Carnivore/Piscivore.