Sedan (Lagerstätte)
| Sedan | |
|---|---|
| Stratigraphic range: [1] | |
| Lithology | |
| Primary | Dark grey claystone |
| Location | |
| Coordinates | 49°42′N 4°54′E / 49.7°N 4.9°E |
| Approximate paleocoordinates | 39°54′N 20°06′E / 39.9°N 20.1°E |
| Region | Grand Est |
| Country | France |
The Sedan Lagerstätte is a Pliensbachian, early Jurassic fossil Lagerstätte from the Ardennes, eastern France. It provides numerous well-preserved fossils of diverse echinoderms.[1]
The estimated paleocoordinates of 39°54′N 20°06′E / 39.9°N 20.1°E are taken from the Paleobiology Database.
Biota
| Genus | Species | Notes |
|---|---|---|
| Balanocrinus | B. gracilis | An Isocrinida crinoid. |
| Palaeocomaster | P. benthuyi | A Comatulid crinoid.[2] |
| Inexpectacantha | I. acrobatica | An Ophiacanthida ophiuroid. |
| Palaeocoma | P. milleri | An Ophiacanthida ophiuroid. |
| Eirenura | E. papillata | An Ophiurida ophiuroid. |
| Sinosura | S. brodiei | An Ophiurida ophiuroid. |
| Ophiomusium | O. murravii | An Ophiurida ophiuroid. |
| Ophiura? | O? astonensis | An Ophiurida ophiuroid. The attribution of jurassic species to the extant genus Ophiura is untenable. |
| Aspiduriella? | A?sp. | Might represent a relict species of the triassic Ophiurida Aspiduriella. |
| Tropidaster | T. pectinatus | Asteroidea. |
| Plumaster | sp.nov. | Asteroidea. |
| Achistrum | A. cf.monochordatum | Holothuroidea. |
| Binoculites | B. jurassica | Holothuroidea. |
| Indet. | Indet. | A new species of chiridotid. |
| Eodiadema | sp. | An Echinoida. |
| Modiolus | sp. | A bivalve. |
Paleoecology and environment
The echinoderms and bivalves are present in repeated distinct beds, suggesting that they were regularly buried by storm-related sedimentation events (obrution). It is interpreted as intervals of reduced sediment input followed by high-energy storm deposition. The general climate was warm.[1]
References
- 1 2 3 4 Thuy, Ben; Gale, Andrew S.; Reich, Mike (2 December 2010). "A new echinoderm Lagerstätte from the Pliensbachian (Early Jurassic) of the French Ardennes". Swiss Journal of Palaeontology. 130: 173–185. doi:10.1007/s13358-010-0015-y. ISSN 1664-2384.
- ↑ Hess, Hans (25 September 2013). "Origin and radiation of the comatulids (Crinoidea) in the Jurassic". Swiss Journal of Palaeontology. 133: 23–34. doi:10.1007/s13358-013-0061-3. ISSN 1664-2384.