Gérard Paul Deshayes (; 13 May 1795 – 9 June 1875) was a French
geologist
A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, ...
He was born in Nancy, his father at that time being professor of experimental physics in the École Centrale of the
département
In the administrative divisions of France, the department (, ) is one of the three levels of government under the national level (" territorial collectivities"), between the administrative regions and the communes. There are a total of 101 ...
medicine
Medicine is the science and Praxis (process), practice of caring for patients, managing the Medical diagnosis, diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, ...
in
Strasbourg
Strasbourg ( , ; ; ) is the Prefectures in France, prefecture and largest city of the Grand Est Regions of France, region of Geography of France, eastern France, in the historic region of Alsace. It is the prefecture of the Bas-Rhin Departmen ...
, and afterwards took the degree of ''bachelier ès lettres'' in
Paris
Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...
in 1821; but he abandoned the medical profession in order to devote himself to
natural history
Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is cal ...
. For some time he gave private lessons on
geology
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...
, and subsequently became professor of natural history in the
Muséum National d'Histoire Naturelle
The French National Museum of Natural History ( ; abbr. MNHN) is the national natural history museum of France and a of higher education part of Sorbonne University. The main museum, with four galleries, is located in Paris, France, within the Ja ...
.
He was distinguished for his researches on the
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...
mollusc
Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...
a of the
Paris Basin
The Paris Basin () is one of the major geological regions of France. It developed since the Triassic over remnant uplands of the Variscan orogeny (Hercynian orogeny). The sedimentary basin, no longer a single drainage basin, is a large sag in ...
and of other areas
Cenozoic
The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three g ...
cover. His studies on the relations of the fossil to the recent species led him as early as 1829 to conclusions somewhat similar to those arrived at by Lyell, to whom Deshayes rendered much assistance in connection with the classification of the, then,
Tertiary
Tertiary (from Latin, meaning 'third' or 'of the third degree/order..') may refer to:
* Tertiary period, an obsolete geologic period spanning from 66 to 2.6 million years ago
* Tertiary (chemistry), a term describing bonding patterns in organic ch ...
system into
Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
,
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...
and
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58André Étienne d'Audebert de Férussac, he co-authored an important study on terrestrial and
river
A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...
mollusk
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...
s titled ''Histoire naturelle générale et particulière des Mollusques terrestres et fluviatiles'' (1820-1851). In 1839 he began the publication of his ''Traité élémentaire de conchyliologie'', the last part of which was not issued until 1857. In the same year (1839) he went to
Algeria
Algeria, officially the People's Democratic Republic of Algeria, is a country in the Maghreb region of North Africa. It is bordered to Algeria–Tunisia border, the northeast by Tunisia; to Algeria–Libya border, the east by Libya; to Alger ...
for the French government, and spent three years in explorations in that country. His principal work, which resulted from the collections he made, ''Mollusques de l'Algérie'', was issued (incomplete) in 1848.
He was a member of the
Société Géologique de France
The Société géologique de France (SGF) is a French learned society founded on 17 March 1830. As of 2006, it counts 1,200 members.
History
At its creation, its statutes indicate is to "compete for the advancement of Earth Sciences and Planets, ...
Geological Society of London
The Geological Society of London, known commonly as the Geological Society, is a learned society based in the United Kingdom. It is the oldest national geological society in the world and the largest in Europe, with more than 12,000 Fellows.
Fe ...
His publications included:
*''Description des coquilles fossiles des environs de Paris'' (2 vols. and atlas, 1824-1837)
*''Description de coquilles caractéristiques des terrains.– Paris: F. G. Levrault, 1831.– 264 pp., 14 pls.''
*''Mollusques. In: Saint-Hilaire G., Deshayes G., Saint-Vincent B., Saint-Vincent B. Expédition scientifique de Morée. Section des sciences physiques. Tome III. Première partie. Zoologie. Première section.– Animaux vertébrés, mollusques et polypies.– Paris-Strasbourg: F. G. Levrault., 1832.– p. 81-203, pls. 18-26.''
* ''Traité élémentaire de conchyliologie avec les applications de cette science à la geologie.''
** (1839-1853) Premiere Partie - Introduction (part 1 - Introduction)
** (1843-1850) Seconde Partie - Conchiféres dimyaires (Part 2)
** (1839-1853) Explication des planches (Explanation of plates)
** (1839-1857) Atlas (Atlas of plates)
*''Description des animaux sans vertèbres découverts dans le bassin de Paris'' (3 vols. and atlas, 1856-1866)
*''Catalogue des mollusques de l'île de la Reunion'' (1863).