| System (period) | Series (epoch) | Stage (age) | Lower boundary, Ma | |
|---|---|---|---|---|
| Cretaceous | Lower | Berriasian | ~145 | |
| Jurassic | Upper (Late) | Tithonian | 149.2±0.7 | |
| Kimmeridgian |  154.8±0.8
| |||
| Oxfordian | 161.5±1.0 | |||
| Middle | Callovian | 165.3±1.1 | ||
| Bathonian | 168.2±1.2
| |||
| Bajocian | 170.9±0.8
| |||
| Aalenian | 174.7±0.8
| |||
| Lower (Early) | Toarcian | 184.2±0.3
| ||
| Pliensbachian | 192.9±0.3
| |||
| Sinemurian | 199.5±0.3
| |||
| Hettangian | 201.4±0.2
| |||
| Triassic | Upper | Rhaetian | older | |
| Subdivisions and "golden spikes" according to IUGS as of September 2023[1] | ||||
The Bathonian is a third stage of the Middle Jurassic series, corresponding to the Bathonian age of the Middle Jurassic epoch. It lasted from approximately 168.2 Ma to around 165.3 Ma (million years ago). The Bathonian age succeeds the Bajocian age and precedes the Callovian age.
Megalosaurus, the first described non-avian dinosaur, in known from the Bathonian.
Definition[]
The GSSP of the Bathonian stage was ratified in 2008. The lower boundary is fixed in the Ravin du Bès, Bas-Auran area in France, and related to the first appearance of the ammonite Gonolkites convergens. It also correlates with the base of Zigzagiceras zigzag Zone.[2]
Bathonian life[]
In the warm seas that covered the territory of Europe, active evolution of bony and cartilaginous fish took place. Various sea fish were discovered in the Bathonian sediments near Oxford, UK. Fossil specimens include Ceratodus phillipsi, Mesodon, Microdon, Lepidotus, Leptolepis and Aspidorhynchus. Several cartilaginous fish including chimaeran Ischyodus and Ganodus as well as euselachian Breviacanthus have also been found there. The increased abundance of plankton has led to the emergence of the largest marine species since the Triassic. In 2015, an indeterminate species of Leedsichthys, one of the largest fish of all time, was found in the Bathonian strata of Calcaire de Creully Formation in France.
The archipelagos scattered in these seas were inhabited by rare theropod and sauropod dinosaurs. Megalosaurus, a large carnivorous theropod, was hunted Cetiosaurus, a huge sauropod. Both of them inhabited the coasts and were found in marine sediments along with Teleosaurus, a sea reptile related to crocodiles. Dubreuillosaurus, a close relative of Megalosaurus, was discovered in shallow sea sediments of the Bathonian Calcaires de Caen Formation in France. Since only shellfish and fish were found with this animal, it can be assumed that some megalosaurids were highly dependent on the sea and, apparently, could swim at least short distances.
References[]
- ↑ "Latest version of international chronostratigraphic chart". International Commission on Stratigraphy. https://stratigraphy.org/chart#latest-version.
- ↑ "GSSP Table - Mesozoic Era". https://timescalefoundation.org/gssp/index.php?parentid=35.