Holonema

Holonema Temporal range: Givetian to Frasnian, 387.7–372.2 Ma PreꞒ Ꞓ O S D C P T J K Pg N
H. westolli
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	†Placodermi
Order:	†Arthrodira
Suborder:	†Brachythoraci
Family:	†Holonematidae
Genus:	†Holonema Newberry, 1889
Type species
Pterichthys rugosum Claypole, 1883
Species
H. rugosum (Claypole, 1883) H. arcticum Marik-Kurik, 1975 H. bruehni Markus, 1998 H. harmae Mark, 1953 H. farrowi Stevens, 1964 H. obrutshevi Mark, 1953 H. ornatum Traquair, 1903 H. haiti Denison, 1968 H. radiatum Obruchev, 1932 H. westolli Miles, 1971
Synonyms
Pterichthys rugosus Claypole, 1883 ?Glyptaspis eastmanni Swartz, 1913 Holonema horridum Cope, 1892 Holonema rohoni nomen nudum Obruchev 1931

Holonema is an extinct genus of relatively large, barrel-shaped arthrodire placoderms that were found in oceans throughout the world from the Mid to Late Devonian, when the last species perished in the Frasnian-Fammian extinction event. Most species of the genus are known from fragments of their armor, but the Gogo Reef species, H. westolli, is known from whole, articulated specimens.