| System (period) | Series | Stage (age) | Lower boundary, Ma | |
|---|---|---|---|---|
| Neogene | Miocene | Aquitanian | 23.03 | |
| Paleogene | Oligocene | Chattian |  27.82
| |
| Rupelian | 33.9
| |||
| Eocene | Priabonian | 37.71
| ||
| Bartonian | 41.2 | |||
| Lutetian | 47.8
| |||
| Ypresian | 56.0
| |||
| Paleocene | Thanetian | 59.2
| ||
| Selandian | 61.6
| |||
| Danian | 66.0
| |||
| Cretaceous | Upper | Maastrichtian | older | |
| Subdivisions and "golden spikes" according to IUGS as of September 2023[1] | ||||
The Rupelian is a lower stage of the Oligocene series, corresponding to the Rupelian age of the Oligocene epoch. It lasted from approximately 33.9 Ma to around 27.82 Ma (million years ago). It is preceded by the Priabonian age of the Eocene and is followed by the Chattian age of the Oligocene. The earliest alepocephaliforms, desmostylians and felids (cats) as well as last leptictids are known from this stage.
Definition[]
The GSSP of the Rupelian stage and the whole Oligocene series was ratified in 1992. The lower boundary is fixed in the base of a 0.5m thick greenish-grey marl bed near Ancona, Italy, and related to the last appearance of the foraminifer genera Hantkenina and Cribrohantkenina.[2]
Rupelian life[]
Numerous bivalves (Pycnodonte, Astarte, Yoldia, Spondylus) and gastropods (Tornatellaea, Architectonica, Diodora, Pleurofusia) lived on the seabed. Among arthropods, insects reached the greatest numbers and lived almost all over the world. Oligaeschna kvaceki, a dragonfly, and Sulcalydus kalabisi, a broad-headed bug, inhabited the sea coasts.
The evolution of bony fishes continued. Palaeotroctes and Vachalia, the earliest known alepocephaliforms, inhabited deep seas in the Rupelian. Other bony fishes that shared the environment with them include stomiatiforms (Vinciguerria), myctophiforms (Eomyctophum), perciforms (Serranus), scombriforms (Anenchelum) and stomiatiforms (Scopeloides). These various fishes became targets for lamniform sharks like Cetorhinus and Alopias. The huge Otodus angustidens also existed in this age.
Various amphibians (Palaeobatrachus), turtles (Bergouniouxchelys) and crocodiles (Diplocynodon) inhabited rivers and lakes. Plotopterid birds like Tonsala and Klallamornis hunted in seas.
Olympicetus
Important changes have occurred in the species composition of marine mammals. After the extinction of archaic whales, toothed (Olympicetus) and baleen (Fucaia, Borealodon) whales, feeding on plankton, spread into the seas. Desmostylians, the plant-eating mammals, appeared. Behemotops, the oldest of them, is known from the Rupelian strata of Pysht Formation, USA. Eosiren, a sea cow, lived in rivers in northern Africa.
A model of Phiomia
Among land mammals, the largest numbers have reached rodents (Talahphiomys, Phiomys, Metaphiomys, Nonanomalurus) and bats (Philisis, Hipposideros, Dhofarella, Chibanycteris). The last leptictids, such as Leptictis, are known from the Rupelian stage. Herbivorous land ungulates of the time include anthracotheriids (Bothriogenys), swines (Propalaeochoerus, Hyotherium), arsinoitheriids (Arsinoitherium), proboscideans (Omanitherium, Phiomia) hyracoids (Thyrohyrax) and Paraceratherium, a relative of rhinos and one of the largest land mammal of all time. A variety of carnivorous mammals preyed on these animals. Primitive creodonts (Masrasector) and entelodontids (Entelodon, Paraentelodon) were forced to compete with carnivorans, among which the most ancient cats (Proailurus) appeared. The primates of that time (Shizarodon, Omanodon, Propliopithecus, Oligopithecus) lived in trees, where they ate fruits and small animals.
References[]
- ↑ "Latest version of international chronostratigraphic chart". International Commission on Stratigraphy. https://stratigraphy.org/chart#latest-version.
- ↑ "GSSP Table - Cenozoic Era". https://timescalefoundation.org/gssp/index.php?parentid=2.