| System (period) | Series | Stage (age) | Lower boundary, Ma | |
|---|---|---|---|---|
| Permian | Cisuralian | Asselian | 298.9±0.15 | |
| Carboniferous | Pennsylvanian | Upper | Gzhelian | 303.7±0.1 |
| Kasimovian | 307.0±0.1 | |||
| Middle | Moscovian | 315.2±0.2 | ||
| Lower | Bashkirian |  323.2±0.4
| ||
| Mississippian | Upper | Serpukhovian | 330.9±0.2 | |
| Middle | Visean | 346.7±0.4
| ||
| Lower | Tournaisian | 358.9±0.4
| ||
| Devonian | Upper | Famennian | older | |
| Subdivisions and "golden spikes" according to IUGS as of September 2023[1] | ||||
The Serpukhovian is a third and upper stage of the Mississippian subsystem of the Carboniferous system, corresponding to the Serpukhovian age of the Mississippian part of the Carboniferous period. It lasted from approximately 330.9 Ma to around 323.2 Ma (million years ago). It is preceded by the Visean age of the Mississippian and is followed by the Bashkirian age of the Pennsylvanian. The earliest winged insects are known from this stage.
Definition[]
As of 2024, there is still no GSSP of the Serpukhovian stage. Candidates are Verkhnyaya Kardailovka (Urals, Russia) and Nashui (China). The first appearance of the conodont species Lochriea ziegleri is suggested as a marker of the lower boundary.[2]
Serpukhovian life[]
Cleiothyridina sublamellosa, a brachiopod
Marine benthic fauna of the Serpukhovian included cnidarians, brachiopods (Cleiothyridina, Nucleospira, Brachythyris), bivalves (Aviculopecten, Sphenotus, Wilkingia) and gastropods (Amphiscapha, Retispira, Pseudozygopleura). Cephalopods like nautilid Aphelaeceras and ammonoid Neoglyphioceras hunted in water column and protected themselves from predators with the help of hard shells. Xiphosurids (Boeotiaspis) and rare trilobites as Mahaiella fed on the seabed. Campylocephalus, a eurypterid, inhabited freshwater lakes of that time. The number of land arthropods increased. Various centipedes (Arthropleura), scorpions and spider-like trigonotarbids (Euphrynus) lived in forests that grew in swamps and along the shores of lakes.
Kirchnerala treintamil, an early winged insect
During Serpukhovian, one of the most important events in the history of the Earth took place: the first flying animals appeared. They were insects. From the Serpukhovian strata of the Guandacol Formation in Argentina, kukalopteran (Kirchnerala), argentinopteran (Argentinala), and eugeropteran (Tupacsala) insects have been collected. Another winged insect, Delitzschala of the order Palaeodictyoptera, is known from the Sandersdorf Formation of Germany. Wings allowed insects to better avoid dangerous predators and spread over longer distances in a very fast time. Due to this feature, insects from this age began to become the dominant arthropod group.
Cyranorhis fossil
Among chordates, conodonts were still numerous. Serpukhovian genera include Idioprioniodus, Gnathodus and Lochriea. A variety of cartilaginous fish including petalodontiforms (Belantsea, Netsepoye, Petalorhynchus), symmoriiforms (Stethacanthus, Falcatus, Damocles), chondrenchelyiforms (Harpagofututor) and other groups lived in the seas. Fossils of bony fishes, including coelacanthiforms (Lochmocercus, Caridosuctor) and palaeonisciforms (Cyranorhis, Wendyichthys), have been found in the Serpukhovian marine strata of the Fergus County, Montana, USA. The largest vertebrate predator was probably Rhizodus, which lived in coastal waters.
Important evolutionary changes for vertebrates occurred in swampy equatorial forests. Stegocephalians like Crassigyrhinus and Greererpeton had small limbs and were likely fully aquatic. Temnospondyls, the true tetrapods, needed water to reproduce, but could live on land too. The footprints of Hylopus from the Bluefield Formation in Virginia, USA, confirm this. More derived tetrapods like Papposaurus and Proterogyrinus could move further and further from the water, but probably laid eggs in water or damp places.
References[]
- ↑ "Latest version of international chronostratigraphic chart". International Commission on Stratigraphy. https://stratigraphy.org/chart#latest-version.
- ↑ "GSSP Table - Paleozoic Era". https://timescalefoundation.org/gssp/index.php?parentid=77.