Belemnite
Belemnite is the common name applied to an extinct order (Belemnoida) of
molluscs belonging to the cephalopod class. Today the n cephalopods include
the squid, octopus, and pearly Nautilus.
 The
belemnoid animal was covered by a leathery skin and had an internal shell.
It also had tentacles that protruded forward and so it was closely related
to the present day squid. It also had a siphon system that squirted water
forward that moved the animal backwards by this jet propulsion system.
The name is believed to have originally been derived from the Greek
language 'belemnon', which is today translated as meaning the name of an
object that is shaped like a javelin.
The Belemnites were believed to have been around for 140 million years.
They first appeared on Earth some 208 million years ago, It is believed that
they evolved from the same ancestors as the
Ammonites.
Belemnites were a major source of food for many sea creatures at the
time, for example belemnite hooks have been discovered in the stomach of
plesiosaurs and shark (Hybodus). After spawning the belemnites died just
like today's squid. |
