''Dartmuthia'' is an extinct genus of primitive jawless

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

that lived in the

Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...

period. Fossils of ''Dartmuthia'' have been found in Himmiste Quarry, on the island of

Saaremaa Saaremaa (; ) is the largest and most populous island in Estonia. Measuring , its population is 31,435 (as of January 2020). The main island of the West Estonian archipelago (Moonsund archipelago), it is located in the Baltic Sea, south of Hi ...

Estonia Estonia, officially the Republic of Estonia, is a country in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the Baltic Sea across from Sweden, to the south by Latvia, and to the east by Ru ...

. It was first described by William Patten. ''Dartmuthia'' is one of the only osteostracans in which material of the trunk and tail behind the armored head shield have been found. Since the mouth is positioned on the underside of the head ''Dartmuthia'' is presumed to have dwelled on the ocean floor, sucking its food into its mouth.

References

Osteostraci genera Fossils of Estonia Silurian fish of Europe {{Paleo-jawless-fish-stub