Benneviaspidida is an order of

osteostracan The class Osteostraci (meaning "bony shells") is an extinct taxon of bony-armored jawless fish, termed "ostracoderms", that lived in what is now North America, Europe and Russia from the Middle Silurian to Late Devonian. Anatomically speaking, ...

jawless fishes which lived in the

Early Devonian The Early Devonian is the first of three Epoch (geology), epochs comprising the Devonian period, corresponding to the Lower Devonian Series (stratigraphy), series. It lasted from and began with the Lochkovian Stage , which was followed by the P ...

. The fishes in this order have a flat headshield and are dorsoventrally depressed. The first canal to lateral sensory field bifurcates near the

orbit In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a p ...

Phylogeny

The

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

below is adapted from Sansom (2009):

References

External links

Benneviaspidida at Palaeos

Osteostraci by Philippe Janvier

Early Devonian osteostracans from Russia
{{Taxonbar, from=Q4889790 Osteostraci Prehistoric jawless fish orders Devonian jawless fish Early Devonian first appearances Early Devonian taxonomic orders Early Devonian extinctions