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The Furongian is the fourth and final epoch and series of the Cambrian. It lasted from to million years ago. It succeeds the Miaolingian series of the Cambrian and precedes the Lower Ordovician Tremadocian Stage. It is subdivided into three stages: the Paibian, Jiangshanian and the unnamed 10th stage of the Cambrian.
| Lower Ordovician | |
| Floian | |
| Tremadocian | |
| Furongian | |
| Stage 10 | |
| Jiangshanian | |
| Paibian | |
| Miaolingian | |
| Guzhangian | |
| Drumian | |
| Wuliuan |
The Furongian can be divided into a number of :
| Furongian | Stage 10 | Saukia zone (upper part), Eurekia apopsis zone, Tangshanaspis Zone, Parakoldinioidia zone, Symphysurina zone | Lotagnostus americanus (undecided) |
| Jiangshanian | Ellipsocephaloides zone, Saukia zone (lower part) | Agnostotes orientalis | |
| Paibian | ? (?) | Glyptagnostus reticulatus | |
| Aphelaspis Zone | |||
Steptoean positive carbon isotope excursion (SPICE) occurred in close proximity in time to the Miaolingian–Furongian boundary (and, accordingly, the Guzhangian–Paibian boundary). This event is recorded on almost all Cambrian paleocontinents, but its exact causes are not fully understood. It is assumed that it may be associated with the Sauk megasequence, which in turn is associated with sea level changes; anoxic event or occurrence of euxinia in ocean waters; or the trilobite biomere turnover.
From the Furongian to the Early Ordovician, around 495-470 Ma, the mantle plume activity, known as the Ollo de Sapo magmatism, occurred on the North-Western territory of the Gondwana which is now the Iberian Peninsula.
8502 specimens of trilobite-Agnostoidea fauna have been collected from the Furongian strata of the Alum Shale Formation of Bornholm, Denmark. Described gerena include Ctenopyge, Eurycare, Leptoplastus, Olenus, Parabolina, Peltura, Protopeltura, Sphaerophthalmus, Lotagnostus and Triangulopyge. Benthos graptolites, including genera Rhabdopleura, Dendrograptus, Callograptus and Siberiograptus, were found in the Furongian sediments of South China.
Paleontology
Researchers have been noted that the significant macroscopic soft-bodied animals that lived between the Cambrian Explosion and the Great Ordovician Biodiversification Event were not discovered. In 2019, this time interval was named the Furongian Biodiversity Gap by Harper et al. This gap has been characterized as probably caused by lack of rocks, environmental events or a specific palaeogeography and extreme climates of the late Cambrian. However, a review of the literature and locations with Cambrian deposits showed that the gap is caused by the insufficient presence of Furongian deposits in sufficiently studied areas, as well as the lack of attention to of this interregnum. Later discoveries of the Furongian deposits in South China have allowed for a better understanding of the biostratigraphy and fluctuations in species diversity of this epoch.
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