- from the
Middle Silurian to Late Devonian.
Anatomically speaking, the
osteostracans,
especially the
Devonian species, were
among the most
advanced of all...
- Gr****: ἀσπίς aspís, 'shield') is a
possibly monotypic genus of
extinct osteostracan agnathan vertebrate. It was a trout-sized
detritivorous fish that lived...
- Keating,
Joseph N.; Sansom,
Robert S.; Purnell, Mark A. (2012). "A new
osteostracan fauna from the
Devonian of the
Welsh Borderlands and
observations on...
- most do have a
dorsal or a
caudal fin. Some
fossil agnathans, such as
osteostracans and pituriaspids, did have
paired fins, a
trait inherited in
their jawed...
-
Benneviaspidida is an
order of
osteostracan jawless fishes which lived in the
Early Devonian. The
fishes in this
order have a flat
headshield and are dorsoventrally...
-
Cephalaspidomorphs are a
superclass of
jawless fishes named for
Cephalaspis of the
osteostracans. Most
biologists regard this
taxon as extinct, but the name is sometimes...
-
Superclass †Cephalaspidomorphi (cephalaspidomorphs)
class †Osteostraci (
osteostracans)
class †Galeaspida (galeaspids)
class †Pituriaspida (pituriaspids) Superclass...
-
Zenaspidida is an
extinct order of
osteostracans, a
group of
jawless stem-gnathostomes. They
possessed a
distinct headshield,
which varied in
width to...
-
Janaspis is an
extinct genus of
osteostracan, that
lived in the
early Devonian period in Britain. It is
characterised by a
number of
features of its armoured...
- the anal region. The
dorsal portion of its head
armor differs from
osteostracans in that the
orbits of the eyes are set
apart from each other, and that...
