-
order Ammonitida, the only
remaining group of
ammonoids from the Jur****ic up
until their extinction.
Ammonoids exhibited considerable diversity over their...
- cephalopods,
along with the
extinct ammonoids (ammonites) and
living coleoids (such as squid, octopus, and kin).
While ammonoids and
coleoids are monophyletic...
- However,
ammonoid fossils switch over to the
lower Acutimitoceras (Stockumites)
genozone (UD VI-F),
indicating that post-Devonian
ammonoids were beginning...
- 99 million
years ago.
During this time, the
first ammonoids appeared,
descending from
bactritoid nautiloids.
Ammonoids during this time
period were
simple and differed...
- Ammonitida, or true ammonites, are an
order of
ammonoid cephalopods that
lived from the Jur****ic
through Paleocene time periods,
commonly with intricate...
-
period (231
million years ago). They are
considered ancestors of the
ammonoids, as well as of the
coleoids (octopus, squid, cuttlefish, and the extinct...
-
somewhat simpler,
being either straight or
slightly curved,
whereas later ammonoids showed suture patterns of
increasing complexity. One
explanation for this...
- the
superficially similar Baculites and
related Cretaceous orthoconic ammonoids. Both are long and
tubular in form, and both are
common items for sale...
-
outer edge as in most
ammonoids. Developmentally, the
siphuncle in
clymeniids starts off ventrally, like that in
other ammonoids, but
after the
first few...
-
Prolecanitida is an
order of
extinct ammonoid cephalopods, the
major Late
Paleozoic group of
ammonoids alongside the
order Goniatitida. Prolecanitids...
