Hettangian
The Hettangian is the first stage of the Early Jurassic Epoch. It spans the time between 199.6 ± 0.6 Ma and 196.5 ± 1 Ma (million years ago). The stage follows the Rhaetian Stage of the Triassic Period.
The stage takes its name from Hettange-Grande, a town in northern France, just south of the border with Luxembourg on the main road from Luxembourg City to Metz.
In Europe this period, together with the Sinemurian, is also known as the Lower (or Blue) Lias Stage.
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| Ichthyosauria of the Hettangian | ||||
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| Taxa | Presence | Location | Description | Images |
| From Hettangian to Sinemurian | Belgium, England, Germany | Among the best known ichthyosaur genera, was smaller than most of its relatives, measuring 2 m (6 ft 8 inches) in length. | ||
| Mammaliaformes of the Hettangian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Ornithischians of the Hettangian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| From Hettangian to Sinemurian | Upper Elliot Formation, Lesotho and Cape Province, South Africa | Considered the most basal member of the family Heterodontosauridae | ||
| From Hettangian to Sinemurian | Lesotho | As the only fossil known of it is a partial jawbone with three teeth, Fabrosaurus is a nomen dubium and may in fact be the same as Lesothosaurus. | ||
| Upper Elliot Formation, Cape Province, South Africa | A small, fleetfooted ornithischian that reached a maximum size of about 3 feet. The hand of Heterodontosaurus had five fingers, two of which seem to be opposable. allowing Heterodontosaurus to grasp and manipulate food.
Another interesting feature is the specialization of teeth which gave rise to the animal's name. At the front of the jaw beside the beak were small teeth likely used for chopping off leaves and stems. |
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| From Hettangian to Sinemurian | Upper Elliot Formation, Orange Free State, South Africa | A heterodontosaurid ornithischian | ||
| From Hettangian to Sinemurian | Upper Elliot Formation, Cape Province, South Africa | A small herbivore dinosaur despite long canines it sported in its jaws; due to this unique characteristic it is very clearly allied to Heterodontosaurus | ||
| From Hettangian to Sinemurian | Charmouth, West Dorset, England; Kayenta Formation, Arizona, USA | A genus of quadrupedal, lightly plated, herbivorous dinosaur about 4 meters long (13 ft) | ||
| Arizona, USA | A bipedal armored herbivor, was around 1.3 m (4 ft 4 inches) long, 0.5 m (18 in) tall at the hips, and weighed 10 kg (22 lb). | |||
| From Hettangian to Sinemurian | Stormberg Series Formations, South Africa, Lesotho | A primitive ornithischian, about 2 meters long. The proportions of the posterior limbs show differences with those of Lesothosaurus, and reveal a lower ability to run | ||
| Plesiosauria of the Hettangian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Hettangian and Toarcian | Barrow-upon-Soar, Leicestershire, England | A genus of sauropterygian carnivorous reptile belonging to the pliosaur superfamily, it was about 7m long. | ||
| Jurassic period | ||
|---|---|---|
| Lower/Early Jurassic | Middle Jurassic | Upper/Late Jurassic |
| Hettangian | Sinemurian Pliensbachian | Toarcian |
Aalenian | Bajocian Bathonian | Callovian |
Oxfordian | Kimmeridgian Tithonian |

