- present. (The librigena, or ch**** spines,
detach during moulting.) In
ptychopariids,
short bladelike genal spines are
often present on the tips of the librigena...
-
Bergeroniellus B.
spinosus Redlichiid trilobite Binodaspis B.
secunda Ptychopariid trilobite Sinskolutella S.
ordinata Bradoriid Yakutingella Y. intricata...
-
earliest trilobites known from the
fossil record are
redlichiids and
ptychopariid bigotinids dated to
around 520
million years ago.
Contenders for the...
- with
disparate groups of
other ptychopariids,
which make it
difficult to
place within other established ptychopariid families. The
generic name translates...
-
Eoproetus is an
extinct genus of
ptychopariid trilobite in the
family Ptychopariidae. It
lived what is now
China during the
Cambrian Period,
which lasted...
-
Holotrachelidae and
Hystricuridae (considered
Proetida before),
combined with the
Ptychopariid families Alokistocaridae, Crepicephalidae, Ehmaniellidae, Marjumiidae...
-
Cloacaspis is an
extinct genus of
Olenid Ptychopariid trilobite. It
lived during the
early part of the
Arenig stage of the
Ordovician Period, a faunal...
-
Triarthrus is a
genus of
Upper Ordovician ptychopariid trilobite found in New York, Ohio, Kentucky, and Indiana,
eastern and
northern Canada,
China and...
-
Quitacetra arenata is a
species of
ptychopariid trilobite arthropod from Late Cambrian-aged
deposits in
Quita Cr****, Queensland. Sepkoski, Jack (2002)...
-
Olenidae is a
family of
ptychopariid trilobites. Some genera,
Balnibarbi and Cloacaspis, are
thought to have
evolved a
symbiotic relationship with sulfur-eating...
