- 1844 as a new group,
named "
ostracoderms" to mean 's****-skinned' (from Gr**** ὄστρακον óstrakon + δέρμα dérma).
Ostracoderms have
heads covered with a bony...
- had no
movable jaws,
classified them in 1844 into a new
group "
ostracoderms".
Ostracoderms existed in two
major groups, the more
primitive heterostracans...
-
consisting of both
living (cyclostomes) and
extinct (conodonts, anaspids, and
ostracoderms) species.
Among recent animals,
cyclostomes are
sister to all vertebrates...
-
vertebrates or, at any rate, for the
ensemble of all
ostracoderms and the gnathostomes.
Other ostracoderms, such as the
Galeaspida are now
known to have a...
- and Givetian. In the
middle Devonian the
armored jawless fish
known as
ostracoderms were
declining in
diversity and
instead the
jawed fish were thriving...
-
corresponded to
sharp decline of
jawless fish such as
conodonts and
ostracoderms. The
Silurian system was
first identified by the
Scottish geologist Roderick...
-
parts of the
water column.
Among vertebrates,
jawless armored fish (
ostracoderms)
declined in diversity,
while the
jawed fish (gnathostomes) simultaneously...
- appeared. It was long
thought that the
first true
vertebrates (fish —
Ostracoderms)
appeared in the Ordovician, but
recent discoveries in
China reveal that...
- bony
elements or without, most
notably the conodonts, placoderms, and
ostracoderms. Even
after the
evolution of the
vertebral column in
chondrichthyes and...
-
earliest fish with
dedicated respiratory gills and
paired fins, the
ostracoderms, had
heavy bony
plates that
served as
protective exoskeletons against...
