- present. (The librigena, or ch**** spines,
detach during moulting.) In
ptychopariids,
short bladelike genal spines are
often present on the tips of the librigena...
-
earliest trilobites known from the
fossil record are
redlichiids and
ptychopariid bigotinids dated to
around 520
million years ago.
Contenders for the...
-
ptychopariid (specific name may be
confused with Alokistocare)
Alokistocare harrisi -
alokistocarid ptychopariid Asaphiscus wheeleri -
ptychopariid;...
- with
disparate groups of
other ptychopariids,
which make it
difficult to
place within other established ptychopariid families. The
generic name translates...
-
Triarthrus is a
genus of
Upper Ordovician ptychopariid trilobite found in New York, Ohio, Kentucky, and Indiana,
eastern and
northern Canada,
China and...
-
Olenus is a
genus of
Upper Cambrian ptychopariid trilobite.
Olenus can be
found in the
British Isles, India, Norway, Sweden, Denmark, Newfoundland, Texas...
-
Olenidae is a
family of
ptychopariid trilobites. Some genera,
Balnibarbi and Cloacaspis, are
thought to have
evolved a
symbiotic relationship with sulfur-eating...
-
Eoproetus is an
extinct genus of
ptychopariid trilobite in the
family Ptychopariidae. It
lived what is now
China during the
Cambrian Period,
which lasted...
-
Galeaspis is an
extinct genus of
ptychopariid trilobite in the
family Catillicephalidae.
Species are
found in the
Seletinian Horizon of the Kuyandinian...
-
Matania is an
extinct genus of
ptychopariid trilobite in the
family Catillicephalidae. It
lived from 501 to 490
million years ago
during the Dresbachian...
