La Voulte-sur-Rhône is a commune

Communes of France

The commune is the lowest level of administrative division in the French Republic. French communes are roughly equivalent to incorporated municipalities or villages in the United States or Gemeinden in Germany...

 in the Ardèche

Ardèche

Ardèche is a department in south-central France named after the Ardèche River.- History :The area has been inhabited by humans at least since the Upper Paleolithic, as attested by the famous cave paintings at Chauvet Pont d'Arc. The plateau of the Ardeche River has extensive standing stones ,...

 department in southern France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

.

Population

Lagerstätte

La Voulte-sur-Rhône is a marine Lagerstätte

Lagerstätte

A Lagerstätte is a sedimentary deposit that exhibits extraordinary fossil richness or completeness.Palaeontologists distinguish two kinds....

 (sedimentary deposit) located in France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

. It is Middle Jurassic

Middle Jurassic

The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from 176-161 million years ago. In European lithostratigraphy, rocks of this Middle Jurassic age are called the Dogger....

 (Callovian

Callovian

In the geologic timescale, the Callovian is an age or stage in the Middle Jurassic, lasting between 164.7 ± 4.0 Ma and 161.2 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the Oxfordian....

) in age, and is known for the variety of fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s it produces, including cephalopod

Cephalopod

A cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...

s, such as Proteroctopus ribeti

Proteroctopus ribeti

Proteroctopus ribeti was a primitive octopod that lived in the Middle Jurassic, approximately 164 million years ago. The single fossil specimen assigned to this species originates from the Lower Callovian of Voulte-sur-Rhône in France. It is currently on display at the Musée de Paléontologie de La...

, Rhomboteuthis lehmani

Rhomboteuthis lehmani

Rhomboteuthis lehmani is an extinct species of squid, currently the only described member of its genus. R. lehmani is known from the Lower Callovian of Voulte-sur-Rhône, Ardèche, France....

, and Vampyronassa rhodanica

Vampyronassa rhodanica

Vampyronassa rhodanica is an extinct vampyromorph cephalopod known from around 20 fossils from the Lower Callovian of La Voulte-sur-Rhône, Ardèche, France....

. Fossilized cephalopods are rare, and Voulte-sur-Rhône is prized among paleontologists

Paleontology

Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...

 as one of only a few known localities known to produce such cephalopod fossils. Fossil preservation is by pyrite

Pyrite

The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...

, a geologically rare process. Other sites with pyrite preserved fossils are Beecher's Trilobite Bed and the Hunsrück Slate

Hunsrück Slate

The Hunsrück Slate is a Lower Devonian lithostratigraphic unit, a type of rock strata, in the German regions of the Hunsrück and Taunus. It is a lagerstätte famous for exceptional preservation of a highly diverse fossil fauna assemblage.-Geology:...

.
Also found at the site are ophiuroids

Brittle star

Brittle stars or ophiuroids are echinoderms in the class Ophiuroidea closely related to starfish. They crawl across the seafloor using their flexible arms for locomotion. The ophiuroids generally have five long slender, whip-like arms which may reach up to in length on the largest specimens...

, crustacean

Crustacean

Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...

s, fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

, and other pyritized specimens. The exceptional preservation of the fossils at this site is most likely due to the result of oxygen deficient water at the time of the deposition of the fossils, and possibly repeated sediment blanketing.