-
being librostomes in the
order ptychopariida; and all post-Devoniantrilobites
being in the
order proetida, who are
librostomes. Some
librostomes may not...
- Proetida, Harpetida, and
possibly Phacopida.
These are now
known as the "
Librostome Orders".
Trilobites of the
orders Proetida, Harpetida, and of the family...