Pteraspididae is an extinct family of

heterostracan Heterostraci (Ancient Greek, ἕτερος+ὄστρακον "those itha different shell" i is pl. of -us is an extinct subclass of pteraspidomorph jawless vertebrate that lived primarily in marine and estuary environments. Heterostraci exi ...

vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...

s. It is an Early Devonian-aged family that contains the stereotypical,

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, su ...

-shaped pteraspidids, such as the

type genus In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal f ...

, ''

Pteraspis ''Pteraspis'' (from el, πτερόν 'wing' or 'fin' and el, ἀσπίς 'shield') is an extinct genus of pteraspidid heterostracan agnathan vertebrate that lived from the Lochkovian to Eifelian epochs of the Devonian period in what is now ...

'', and its close relatives ''

Errivaspis ''Errivaspis'' is an extinct genus of pteraspid heterostracan agnathan vertebrate known from fossils at the Wayne Hereford Quarry, of Early Devonian England, and of Podolia, Early Devonian Ukraine. It was originally described by Dr. Errol Ivor ...

'' and '' Rhinopteraspis'', that are popularly thought to have actively swam about in the water column. The elongated

rostral Rostral may refer to: Anatomy * Rostral (anatomical term), situated toward the oral or nasal region * Rostral bone, in ceratopsian dinosaurs * Rostral organ, of certain fish * Rostral scale, in snakes and scaled reptiles Other uses * Rostral colu ...

plate Plate may refer to: Cooking * Plate (dishware), a broad, mainly flat vessel commonly used to serve food * Plates, tableware, dishes or dishware used for setting a table, serving food and dining * Plate, the content of such a plate (for example: ...

is thought to help with their hydrodynamic ability. Various genera are found in various marine and estuarine strata of Early Devonian Europe and North America.

Genera

* †'' Althaspis'' * †''

Blieckaspis ''Blieckaspis priscillae'' is a pteraspidid heterostracan agnathan from the Middle Devonian of North America. ''Blieckaspis priscillae'' was originally described by Robert Denison from incomplete remains from Late Emsian-aged marine strata in W ...

'' * †'' Brachipteraspis'' * †''

'' * †'' Escharaspis'' * †'' Grumantaspis'' * †'' Helaspis'' * †'' Larnovaspis'' * †'' Loricopteraspis'' * †'' Miltaspis'' * †'' Mitraspis'' * †'' Mylopteraspidella'' * †'' Mylopteraspis'' * †'' Podolaspis'' * †''

'' * †'' Rhinopteraspis'' * †'' Stegobranchiaspis''

References

* On the recent discovery of Pteraspidian fish in the upper Silurian rocks of North America. Edward Waller Claypole, Quart. Journ. Geol. Soc. 1885, volume 41, pages 48–64, * Revised classification of Pteraspididae with description of new forms from Wyoming. Robert Howland Denison, Fieldiana. Geology ; v. 20, no. 1,

External links

*
Pteraspididae at fossilworks.org
(retrieved 17 April 2016) * Pteraspidiformes Devonian jawless fish Early Devonian fish Prehistoric jawless fish families Early Devonian first appearances Early Devonian extinctions {{Pteraspidomorphi-stub