- The
anamniotes are an
informal group of
craniates comprising all
fishes and amphibians,
which lay
their eggs in
aquatic environments. They are distinguished...
-
fertilized eggs
within the
mother (marsupial and
placental mammals),
unlike anamniotes (fish and amphibians) that have to
spawn in or
closely adjacent to aquatic...
-
transition from
aquatic to
terrestrial environments. Fish and
amphibians are
anamniotes,
lacking the allantois. In
mammals the
extraembryonic membranes are known...
-
Threatened species in Red List Best
estimate of
percent of
threatened species Anamniotes lay eggs in
water Amphibians 8,707 8,020 92% 2,876 41%
Amniotes adapted...
-
inhibitory neurons. This
structure is very
similar to that
found generally in
anamniotes,
though cartilaginous fishes do show a
layered arrangement of
their pallial...
- birds, and mammals.
Amphibians and fish lack the
amnion and thus are
anamniotes (non-amniotes). The
amnion stems from the extra-embryonic
somatic mesoderm...
-
informally into mammals, sauroids, and
ichthyoids (the
latter containing the
anamniotes),
based on the gaps in
physiological traits and lack of
transitional fossils...
-
groups Image class Estimated number of
described species Group totals Anamniote lack
amniotic membrane so need to
reproduce in
water Jawless Fish Myxini...
- (non-amphibian tetrapods) have
cranial nerves similar to
those of humans. In
anamniotes (fishes and amphibians), the
accessory nerve (XI) and
hypoglossal nerve...
-
Sometimes the
anamniote mesonephros is
called opistonephros to
distinguish it from the
stage of
development in amniotes. In
anamniotes, opisthonephros...
