- discarded. Now, the
ptyctodonts are
regarded as the
sister group of the
Arthrodira and Phyllolepida. Fin
spine of the
ptyctodont, Gamphacanthus, showing...
- placoderms; and, most importantly, that
holocephalians have true teeth,
while ptyctodonts have beak-like
tooth plates.
Ptyctodontids were ****ually dimorphic, with...
-
ptyctodont, but
places it in his "incertae sedis" section.
Individual specimens tend to
resemble the
ptyctodonts from the same
units and
ptyctodonts from...
-
Pseudopetalichthyida as
placoderms consider them to be a
group more
advanced than the
Ptyctodonts. And as such, pro-placoderm
experts consider Pseudopetalichthyida to...
-
acanthoracids resembled scaly chimaeras and (relatively)
heavily armored ptyctodonts. They were
distinguished from
chimaeras by
their large scales and plates...
-
found in the
Strunde valley in the
Paffrather Kalkmulde. As with
other ptyctodonts, the
armor of
Ctenurella was
reduced to a few thin
plates on the head...
-
branching placoderm lineage with claspers.
Other placoderm groups such as
ptyctodonts and
arthrodires display evidence of
similar innovations. The clasper...
-
diagram suggests that E.
primordialis forms a
polytomy with arthrodires,
ptyctodonts, and all
advanced gnathostomes (namely bony fish, tetrapods, acanthodians...
-
Rhamphodopsis is a
genus of
extinct ptyctodont placoderm from the
Middle Devonian Old Red
Sandstone of Scotland.
There are two
species of Rhamphodopsis...
-
placoderms that have been
found in Michigan, the antiarchs, arthrodires, and
ptyctodonts.
Arthrodires reported from
Michigan rocks include Dunkleosteus, Holonema...
