JAWLESS FISH/ PLACODERMS
Bothriolepis
Ancient placoderm "armored fish"
Species: Bothriolepis canadensis
Scaumenac Formation, Scaumenac Bay, Quebec
Upper Devonian, Approx. 370 million years
Cephalaspis
Cephalaspis (meaning "head shield") is a possibly monotypic genus of extinct osteostracan agnathan vertebrate. It was a trout-sized detritivorous fish that lived in the early Devonian.
Doryaspis
Doryaspis ("Dart Shield") (also known by its synonym, "Lyktaspis") is an extinct genus of primitive jawless fish that lived in the Devonian period. Fossils have been discovered in Spitsbergen. The animals had a canteen-shaped body armor, and had large branchial plates that extended out and curved downward in a triangular shape, very similar to those of the pycnosteids.
Young baby "Dunk" (nick-named "Dink").
Lower jaw of famous extinct arthrodire (armored fish), Dunkelosteus terelli
From a young baby "Dunk" (nick-named "Dink").
The associated skull was the most complete ever found.
Cuyahoga County, Ohio, Cleveland Shale, Devonian Period, Approx 380 million years
Dunkleosteus
Dunkleosteus is an extinct genus of large armored, jawed fishes that existed during the Late Devonian period, about 382–358 million years ago. It consists of ten species, some of which are among the largest placoderms to have ever lived: D. terrelli, D. belgicus, D. denisoni, D. marsaisi, D. magnificus, D. missouriensis, D. newberryi, D. amblyodoratus, and D. raveri.
Hemicyclaspis
Hemicyclaspis (lit. 'half-round shield' or 'semicircle plate') is an extinct genus of primitive jawless fish, closely related to Cephalaspis, that lived in the Late Silurian (Pridoli) to Devonian period in what is now Europe and North America. A typical cephalaspid, Hemicyclaspis had a heavily armored, shovel-shaped headshield. It is thought to have been a better swimmer than most of its relatives because of its powerful tail, stabilizing dorsal fin and the keel-shaped hydrodynamic edges of its head shield. Hemicyclaspis probably foraged the ocean floor for food. Give customers a reason to do business with you.
Lamprey
Lampreys (sometimes inaccurately called lamprey eels) are an ancient extant lineage of jawless fish of the order Petromyzontiformes, placed in the superclass Cyclostomata. The adult lamprey may be characterized by a toothed, funnel-like sucking mouth.
Pharyngolepis
Pharyngolepis is an extinct genus of primitive jawless fish that lived in the Silurian period of what is now Norway.
Pharyngolepis had well-developed anal and caudal fins, but no paired or dorsal fins that would have helped stabilise it in the water, and so was probably a poor swimmer, remaining close to the sea bottom. The pectoral fins were instead replaced by bony spines, possibly for protection against predators, and there was a row of spines along the back. It probably scooped up food from the ocean floor.