- type genus, Lituites, are
known only from the
Middle Ordovician and one,
Tyrioceras, is
known from the
Middle and
Upper Ordovician, the last of its kind....
- †Turoceras †Tuyloceras †Tylodiscoceras †Tylonautilus †Tylorthoceras †
Tyrioceras †Ukhtoceras †Uloceras †Ulrichoceras †Umbeloceras †Ungulites †Uralorthoceras...
- Rioceras. The type
species is S. sterna;
genus also
includes S. skua.
Tyrioceras longicameratum Sp. nov
Valid Fang in Fang et al.
Ordovician China A member...
