Palaeomylus

Palaeomylus (meaning 'ancient grinder') is an extinct Devonian ptychodontid placoderm fish.

Palaeomylus
Palaeomylus upper and lower tooth plates from two similarly sized individuals from Wisconsin and Ohio.
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	†Placodermi
Order:	†Ptyctodontida
Family:	†Ptyctodontidae
Genus:	†Palaeomylus Woodward, 1891[1]
Type species
†Palaeomylus frangens (Newberry, 1878)

There are seven species accepted in this genus:^[1][2]

• Palaeomylus hussakofi Bryant, 1935
• Palaeomylus lunaeformis Hussakof & Bryant, 1919
• Palaeomylus minor Bryant, 1935
• Palaeomylus predator Eastman, 1898
• Palaeomylus crassus (Newberry, 1873)
• Palaeomylus frangens (Newberry, 1878)
• Palaeomylus greenei (Newberry, 1889)

Etymology

The generic name is derived from Greek (Palaeo, meaning "ancient") and (mylos, meaning "grinder").

Not to be confused with the junior homonym Palaeomylus (Meng, Wyss, Hu, Wang, Bowen & Koch, 2005), which is an early diverging member of the mammal group Glires.^[3]

Discovery

P. greenei, P. crassus, and the type species P. frangens were originally classified as a species of Rhynchodus, before being moved to a new genus, Palaeomylus, in 1891. The first was found in Wisconsin, while the latter two species were found in Ohio. P. predator was found near Gerolstein, Germany.^[4]