- However,
acanthodians are not true sharks;
their close relation to
modern cartilaginous fish can lead them to be
considered "stem-sharks".
Acanthodians had...
- that are no
longer considered acanthodians. Not
counting their descendants, the
modern chondricthyans, all
acanthodians are extinct.
Extinct genera are...
- that
Osteichthyes evolved from
placoderms like Entelognathus,
while acanthodians are more
closely related to
modern chondrichthyes. Teleostomi, therefore...
-
acanthodians represent a
paraphyletic ****emblage
leading to Chondrichthyes. Some
characteristics previously thought to be
exclusive to
acanthodians are...
- Ordovician-aged
microfossils of what have been
identified as
scales of
either acanthodians or "shark-like fishes", may mark Gnathostomata's
first appearance in...
- the
Chondrichthyes (cartilaginous fish) and the
extinct placoderms and
acanthodians,
which have
endoskeletons primarily composed of cartilage. The vast majority...
-
Silurian was the
diversification of
jawed fish,
which include placoderms,
acanthodians (which gave rise to
cartilaginous fish) and
osteichthyan (bony fish,...
-
Parexus is an
extinct genus of
acanthodian fish.
Acanthodians are
often referred to as ‘spiny sharks’,
although acanthodians are not true
sharks and evolved...
- spine') is an
extinct genus of
acanthodian fish from
Devonian Scotland. It is
among the more
primitive of the
Devonian acanthodians.
Mesacanthus body fossils...
- ventral/pelvic fin and an anal fin on the
underside of the body,
which like
other acanthodians were
supported by
stiff spines at
their front edges. The
whole body was...
