The Thanetian was established by
Swiss geologist
Eugène Renevier in 1873. The Thanetian is named after the
Thanet Formation, the oldest
Cenozoic deposit of the
London Basin, which was first identified in the area of
Kent (southern
England) known as the
Isle of Thanet. The base of the Thanetian Stage is laid at the base of magnetic
chronozone C26n. The references profile (
Global Boundary Stratotype Section and Point) is in the
Zumaia section (43° 18'N, 2° 16'W) at the beach of Itzurun,
Pais Vasco, northern
Spain. Fossils of the unicellular planktonic marine
coccolithophore Areoligeria gippingensis make their first appearance at the base of the Thanetian, and help define its lowest stratigraphic boundary. The top of the Thanetian Stage (the base of the Ypresian) is defined at a strong negative anomaly in δ13C values at the
global thermal maximum at the Paleocene-Eocene boundary. The Thanetian Stage is coeval the lower Neustrian
European land mammal age (it spans the
Mammal Paleogene zone 6 and part of zones 1 through 5.), the upper
Tiffanian and
Clarkforkian North American land mammal ages, the
Riochican and part of the
Itaboraian South American land mammal ages and the upper Nongshanian and
Gashatan Asian land mammal ages. The Thanetian is contemporary with the middle Wangerripian regional stage of
Australia and the upper Ynezian regional stage of
California. It overlaps the obsolete regional stages
Landenian and Heersian of
Belgium. ==Palaeontology==