-
Cyclostome is a
biological term (from the Gr**** for "round mouth") used in a few
different senses: for the
taxon Cyclostomi,
which comprises the extant...
- Traditionally,
cyclostomes have been
divided into two
groups according to the
skeletal organization. In free-walled (or double-walled)
cyclostomes, the exterior...
- to the
gnathostomes than to the
surviving agnathans,
known as
cyclostomes.
Cyclostomes apparently split from
other agnathans before the
evolution of dentine...
-
large notochord as adults, and pouch-shaped
gills (Marspibranchii).
Cyclostomes were
regarded as
either degenerate cartilaginous fishes or primitive...
- with jaws (called gnathostomes) than to
cyclostomes.
Biologists historically disagreed on
whether cyclostomes are a clade. The "vertebrate hypothesis"...
- the
evidence provided by
Heimberg et al. and
prepared to
admit that
cyclostomes are, in fact, monophyletic. The
consequence is that they may tell us...
-
musculature and
nerve cells. It is
housed in the
zooidal exoskeleton,
which in
cyclostomes is
tubular and in
cheilostomes is box-shaped.
Polypides can
undergo cycles...
- the
intervertebral discs. In
other taxa, such as
chondrichthyans and
cyclostomes, it
constitutes a much
greater proportion of the skeleton. It is not...
- to the
gnathostomes than to the
surviving agnathans,
known as
cyclostomes.
Cyclostomes apparently split from
other agnathans before the
evolution of dentine...
- hypothalamus. The
optic chiasm is
found in all vertebrates,
although in
cyclostomes (lampreys and hagfishes), it is
located within the brain. This article...
