Hettangian
first stage and age of the Lower Jurassic series / Early Jurassic epoch
The Hettangian is the earliest age and lowest stage of the Jurassic Period of the geologic timescale. It spans the time between 201.3 ± 0.2 Ma and 199.3 ± 0.3 Ma (million years ago). The Hettangian follows the Rhaetian (part of the Triassic Period) and is followed by the Sinemurian.
In European stratigraphy the Hettangian is a part of the time span in which the Lias was deposited. An example is the British Blue Lias, which has an upper Rhaetian to Sinemurian age. Another example is the lower Lias from the Northern Limestone Alps where well-preserved but very rare ammonites, including Alsatites, have been found.
Stratigraphic definitions
The Hettangian was introduced in the literature by Swiss palaeontologist, Eugène Renevier, in 1864. The stage takes its name from Hettange-Grande, a town in north-eastern France, just south of the border with Luxembourg on the main road from Luxembourg City to Metz.
The base of the Hettangian Stage (which is also the base of the Lower Jurassic Series and the entire Jurassic System) is defined as the place in the stratigraphic column where fossils of the ammonite genus Psiloceras first appear. A global reference profile (a GSSP) for the base was defined 2010 for an exposure of the Kendlbach Formation at the Kuhjoch section in the Karwendel Mountains of western Austria.
The public source identifies “Hettangian” as first stage and age of the Lower Jurassic series / Early Jurassic epoch. This brief keeps that definition visible, then builds a research path around Hettangian, first and stage.
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The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Sep 10, 2025. The linked authority identifier is Q633834. Authority coordinates are 47.484, 11.531. 1 of 1 selected statements include explicit references; 1 carry qualifiers and 0 use preferred rank. The first chronological checks are 1864 and 2010.
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This entry incorporates text from “Hettangian” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.