| System (period) | Series (epoch) | Stage (age) | Lower boundary, Ma | |
|---|---|---|---|---|
| Paleogene | Paleocene | Danian | 66,0 | |
| Cretaceous | Upper (Late) | Maastrichtian |  72.1±0.2
| |
| Campanian | 83.6±0.2
| |||
| Santonian | 86.3±0.5
| |||
| Coniacian | 89.8±0.3
| |||
| Turonian | 93.9
| |||
| Cenomanian | 100.5
| |||
| Lower (Early) | Albian | ~113.0
| ||
| Aptian | ~121.4 | |||
| Barremian | 125.77* | |||
| Hauterivian | ~132.6
| |||
| Valanginian | ~139.8 | |||
| Berriasian | ~145.0 | |||
| Jurassic | Upper | Tithonian | older | |
| Subdivisions and "golden spikes" according to IUGS as of September 2023[1] *A golden spike is seen in chart but not ratified yet. | ||||
The Coniacian is a third stage of the Upper Cretaceous series, corresponding to the Coniacian age of the Late Cretaceous epoch. It lasted from approximately 89.8 Ma to around 86.3 Ma (million years ago). It is preceded by the Turonian and is followed by the Santonian.
The name is given after the French city of Cognac.
Definition[]
The GSSP of the Coniacian stage was ratified in 2021. The lower boundary is fixed in the Salzgitter-Salder Section, Germany, and related to the first appearance of the inoceramid subspecies Cremnoceramus deformis erectus.[2]
Coniacian life[]
In sediments of this age, many marine bivalves (Trigonarca, Pseudolimea, Volviceramus) and cephalopods were found. Ammonite genera include Placenticeras, Paratexanites, Gauthiericeras, Tissotia and Buchiceras. The seas were teeming with a variety of fish, including sharks (Scapanorhynchus, Cretoxyrhina), pachycormiforms (Protosphyraena) and ichthyodectiforms (Ichthyodectes, Xiphactinus). Cimoliasaurus, an elasmosaurid hunted for small fish, and mosasaurs like Clidastes and Angolasaurus were gaining in numbers. Marine turtles like Angolachelys were also numerous.
A variety of dinosaurs lived on land. Herds of titanosaurian sauropods like Kaijutitan and Angolatitan roamed the southern continents. Ornithopods like Macrogryphosaurus have spread throughout the world as well as dromaeosaurids, such as Unenlagia, and alvarezsaurids like Patagonykus. Megaraptors like Murusraptor and abelisaurids like Elemgasem are known mainly from the southern hemisphere. Tyrannosaurids appeared in the northern hemisphere around this time.[3] Avian theropods (birds) like Ichthyornis lived on sea coasts and fed on fish. Pterosaurs like Argentinadraco were still the dominant flying sauropsids.
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.
- ↑ Scherer, Charlie Roger; Voiculescu-Holvad, Christian (2024). "Re-analysis of a dataset refutes claims of anagenesis within Tyrannosaurus-line tyrannosaurines (Theropoda, Tyrannosauridae)". Cretaceous Research: 105780. doi:10.1016/j.cretres.2023.105780