Agnostida Trilobites
 The
trilobites of Order Agnostida (pronounced Ag-nós-t-eh-da)
appeared in the Lower Cambrian where they were diverse and
ubiquitous. They then declined to become rare in the Ordovician
prior to
their complete extinction by the end of the Ordovician. There
is debate about whether agnostids were benthic (living in the
lowest level of a body of water and upper sediment) or pelagic
(living in water not close to the bottom or near to the shore).
Additionally, the systematic position of Order Agnostida remains
unsettled, if not contentious. The agnostids were mostly blind
and exhibited a strong symmetry of cephalon and pygidium size,
making it hard to distinguish front from rear. There are two
Suborders, Eodiscina and Agnostina. Read more about Agnostid
trilobites. |
Trilobite Order Agnostida
Also see: Agnostida Trilobites Classification |
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