''Mawsonia'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

prehistoric Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use o ...

coelacanth Coelacanths ( ) are an ancient group of lobe-finned fish (Sarcopterygii) in the class Actinistia. As sarcopterygians, they are more closely related to lungfish and tetrapods (the terrestrial vertebrates including living amphibians, reptiles, bi ...

fish. It is amongst the largest of all coelacanths, with one quadrate specimen (DGM 1.048-P) possibly belonging to an individual measuring in length. It lived in

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

and

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

environments from the late

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

to the mid-

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

(

Kimmeridgian In the geologic timescale, the Kimmeridgian is an age in the Late Jurassic Epoch and a stage in the Upper Jurassic Series. It spans the time between 154.8 ±0.8 Ma and 149.2 ±0.7 Ma (million years ago). The Kimmeridgian follows the Oxfordian ...

Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...

stages, about 152 to 96

million years ago Million years ago, abbreviated as Mya, Myr (megayear) or Ma (megaannum), is a unit of time equal to (i.e. years), or approximately 31.6 teraseconds. Usage Myr is in common use in fields such as Earth science and cosmology. Myr is also used w ...

) of South America, eastern North America, and Africa. ''Mawsonia'' was first described by British

paleontologist Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geolo ...

Arthur Smith Woodward Sir Arthur Smith Woodward, FRS (23 May 1864 – 2 September 1944) was an English palaeontologist, known as a world expert in fossil fish. He also described the Piltdown Man fossils, which were later determined to be fraudulent. He is not rel ...

in 1907.''Mawsonia''
at

Fossilworks Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cr ...

.org

Description

The

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

has six fins: two on the top of the body, two on the sides, one at the end of its tail and one at the bottom of its tail. Rather than having teeth, the inside of the mouth was covered in small (1-2 mm) denticles. It reached at least in length, although a 2021 study suggest one specimen known from a fragmentary quadrate skull bone possibly exceeded . It was only rivaled in size among coelocanths by the related '' Trachymetopon,'' A 2024 study suggested that very large size estimates should be treated with caution due to being based on fragmentary remains and uncertain scaling relationships between skull elements and total body length.

Taxonomy

The genus was named by

in 1907, from specimens found in the Early Cretaceous (

Hauterivian The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous Epoch or a stage in the Lower Cretaceous Series. It spans the time between 132.6 ± 2 Ma and 125.77 (million years ago). The Hauterivian is preceded by the Valangi ...

) aged Ilhas Group of

Bahia Bahia () is one of the 26 Federative units of Brazil, states of Brazil, located in the Northeast Region, Brazil, Northeast Region of the country. It is the fourth-largest Brazilian state by population (after São Paulo (state), São Paulo, Mina ...

, Brazil.

Fossils have been found on three continents; in South America they have been found in the Bahia Group, Romualdo, Alcântara, Brejo Santo and

Missão Velha Formation The Missão Velha Formation is a Jurassic, late Jurassic geologic geologic formation, formation in northeastern Brazil's Araripe Basin where the states of Pernambuco, Piauí and Ceará come together. The formation is the middle stratigraphic unit ...

s of

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

, and the Tacuarembó Formation of

Uruguay Uruguay, officially the Oriental Republic of Uruguay, is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the A ...

. In

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

, they are known from the Continental Intercalaire of

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 ...

and Tunisia, the Ain el Guettar Formation of

Tunisia Tunisia, officially the Republic of Tunisia, is a country in the Maghreb region of North Africa. It is bordered by Algeria to the west and southwest, Libya to the southeast, and the Mediterranean Sea to the north and east. Tunisia also shares m ...

, the

Kem Kem Group The Kem Kem Group (commonly known as the Kem Kem beds) is a geological group (stratigraphy), group in the Kem Kem region of eastern Morocco, whose strata date back to the Cenomanian stage of the Late Cretaceous. Its strata are subdivided into two ...

of Morocco, and the Babouri Figuil Basin of

Cameroon Cameroon, officially the Republic of Cameroon, is a country in Central Africa. It shares boundaries with Nigeria to the west and north, Chad to the northeast, the Central African Republic to the east, and Equatorial Guinea, Gabon, and the R ...

, spanning from the Late Jurassic, to early Late Cretaceous. Fossils assigned to ''Mawsonia'' have also been found in

Woodbine Formation The Woodbine Group is a geological formation in east Texas whose strata date back to the Early to Middle Cenomanian age of the Late Cretaceous. It is the producing formation of the giant East Texas Oil Field (also known as the "Black Giant") fr ...

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

USA The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous ...

, then part of the island continent

Appalachia Appalachia ( ) is a geographic region located in the Appalachian Mountains#Regions, central and southern sections of the Appalachian Mountains in the east of North America. In the north, its boundaries stretch from the western Catskill Mountai ...

. The type species is ''Mawsonia gigas'', named and described in 1907. Numerous distinct species have been described since then. ''M''. ''brasiliensis'', ''M''. ''libyca'', ''M''. ''minor'', and ''M''. ''ubangiensis'' have all been proposed to be synonyms of ''M''. ''gigas'', although Léo Fragoso's 2014 thesis on mawsoniids finds ''M''. ''brasiliensis'' valid and cautions against synonymizing ''M''. ''minor'' without further examination. Several recent publications consider ''M''. ''brasiliensis'' to be valid as well. Although initially considered to belong to this genus, "''Mawsonia''" ''lavocati'' is most likely referable to ''

Axelrodichthys ''Axelrodichthys'' is an extinct genus of mawsoniidae, mawsoniid coelacanth from the Cretaceous of Africa, North America, North and South America, and Europe. Several species are known, the remains of which were discovered in the Lower Cretaceous ...

'' instead.

Ecology

''Mawsonia'' was native to freshwater and brackish ecosystems. The diet of ''Mawsonia'' and their mechanism of feeding is uncertain. It has been suggested that the denticles were used to crush hard shelled organisms (

durophagy Durophagy is the eating behavior of animals that consume Seashell, hard-shelled or exoskeleton-bearing organisms, such as corals, shelled mollusks, or crabs. It is mostly used to describe fish, but is also used when describing reptiles, including ...

) or that prey was swallowed whole using

suction feeding Aquatic feeding mechanisms face a special difficulty as compared to feeding on land, because the density of water is about the same as that of the prey, so the prey tends to be pushed away when the mouth is closed. This problem was first identifi ...

Description

Taxonomy

Ecology

References

Further reading