Pliensbachian

The Pliensbachian is an age of the geologic timescale and stage in the stratigraphic column. It is part of the Early or Lower Jurassic Epoch or Series and spans the time between 192.9 ±0.3 Ma and 184.2 ±0.3 Ma (million years ago).^[4] The Pliensbachian is preceded by the Sinemurian and followed by the Toarcian.^[5]

Pliensbachian
192.9 ± 0.3 – 184.2 ± 0.3 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Chronology
−205 — – −200 — – −195 — – −190 — – −185 — – −180 — – −175 — – −170 — – −165 — – −160 — – −155 — – −150 — – −145 — – −140 — Mesozoic T Jurassic K LT Early Middle Late EK Rhaetian Hettangian Sinemurian Pliensbachian Toarcian Aalenian Bajocian Bathonian Callovian Oxfordian Kimmeridgian Tithonian Berriasian       ← Triassic–Jurassic extinction event Subdivision of the Jurassic according to the ICS, as of 2024.[1] Vertical axis scale: Millions of years ago
Etymology
Name formality	Formal
Usage information
Celestial body	Earth
Regional usage	Global (ICS)
Time scale(s) used	ICS Time Scale
Definition
Chronological unit	Age
Stratigraphic unit	Stage
Time span formality	Formal
Lower boundary definition	FAD of the Ammonite species Bifericeras donovani and genus Apoderoceras
Lower boundary GSSP	Robin Hood's Bay, Yorkshire, England, UK 54.4069°N 0.4975°W / 54.4069; -0.4975
Lower GSSP ratified	March 2005[2]
Upper boundary definition	Peniche, Portugal
Upper boundary GSSP	FAD of the Ammonite D. (E.) simplex 39.3708°N 9.3853°W / 39.3708; -9.3853
Upper GSSP ratified	2014[3]

The Pliensbachian ended with the extinction event called the Toarcian turnover. During the Pliensbachian, the middle part of the Lias was deposited in Europe. The Pliensbachian is roughly coeval with the Charmouthian regional stage of North America.

Stratigraphic definitions

The Pliensbachian takes its name from the hamlet of Pliensbach in the community of Zell unter Aichelberg in the Swabian Alb, some 30 km east of Stuttgart in Germany. The name was introduced into scientific literature by German palaeontologist Albert Oppel in 1858.

The base of the Pliensbachian is at the first appearances of the ammonite species Bifericeras donovani and genera Apoderoceras and Gleviceras. The Wine Haven profile near Robin Hood's Bay (Yorkshire, England) has been appointed as global reference profile for the base (GSSP).^[6]

The top of the Pliensbachian (the base of the Toarcian Stage) is at the first appearance of ammonite genus Eodactylites.

Biostratigraphy

Pleuroceras spinatum from Lanuéjols, Gard, France

The Pliensbachian contains five ammonite biozones in the boreal domain:

• zone of Pleuroceras spinatum
• zone of Amaltheus margaritatus
• zone of Prodactylioceras davoei
• zone of Tragophylloceras ibex
• zone of Uptonia jamesoni

In the Tethys domain, the Pliensbachian contains six biozones:

• zone of Emaciaticeras emaciatum
• zone of Arieticeras algovianum
• zone of Fuciniceras lavinianum
• zone of Prodactylioceras davoei
• zone of Tragophylloceras ibex
• zone of Uptonia jamesoni