, southern Israel; a variety of
Jerusalem stone (
meleke). The Turonian (French:
Turonien) was defined by the
French paleontologist
Alcide d'Orbigny (1802–1857) in 1842. Orbigny named it after the French city of
Tours in the region of
Touraine (department
Indre-et-Loire), which is the original
type locality. The base of the Turonian Stage is defined as the place where the
ammonite species
Watinoceras devonense first appears in the
stratigraphic column. The official reference profile (the
GSSP) for the base of the Turonian is located in the Rock Canyon anticline near
Pueblo, Colorado (United States, coordinates: 38° 16' 56" N, 104° 43' 39" W). The top of the Turonian Stage (the base of the Coniacian) is defined as the place in the stratigraphic column where the
inoceramid bivalve species
Cremnoceramus rotundatus first appears.
Subdivision The Turonian is sometimes subdivided in Lower/Early, Middle and Upper/Late substages or subages. In the
Tethys domain, it contains the following ammonite
biozones: • zone of
Subprionocyclus neptuni (in the Upper Turonian) • zone of
Collignoniceras woollgari (in the Middle Turonian) • zone of
Mammites nodosoides • zone of
Watinoceras coloradoense or
Watinoceras devonense (last two both in the Lower Turonian) Other important
index fossils are species of the inoceramid
genus Inoceramus (
I. schloenbachi,
I. lamarcki and
I. labiatus). Inoceramids are bivalve
Mollusca related to today's
mussels. == References ==