''Purussaurus'' 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 ...

of giant

caiman A caiman ( (also spelled cayman) from Taíno language, Taíno ''kaiman'') is an alligatorid belonging to the subfamily Caimaninae, one of two primary lineages within the Alligatoridae family (biology), family, the other being alligators. ...

that lived in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

during the

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 ...

epoch, from the Friasian to the

Huayquerian The Huayquerian () age is a period of geologic time (9.0–6.8 Ma) within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification. It follows the Chasicoan and precedes the Montehermosan age. Etymology T ...

in the SALMA classification. It is known from skull material found in the

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 ...

ian and Peruvian Amazon,

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

n Villavieja Formation,

Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

nian Culebra Formation, Urumaco and Socorro Formations of northern

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

Description

The skull length of the largest known individual of the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

, ''P. brasiliensis'' is . It has been estimated that ''P. brasiliensis'' reached about in length, weighing about . Another estimate gave a larger size of in length, ranging from , and in weight, ranging from , with a mean daily food intake of , ranging from . It is also likely that ''Purussaurus'' reached only long and . A 2022 study estimated a length of and a mass of using a phylogenetic approach; and a length of and mass of using a non-phylogenetic approach. As only skulls have been found, the actual length is not certain. Bite force has been estimated to be around 52,500 N (around 5.3

metric ton The tonne ( or ; symbol: t) is a unit of mass equal to 1,000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton in the United States to distinguish it from the non-metric units of the sh ...

s-force), with upper estimates indicating that Purussaurus was capable of generating 69,000 N (around 7 metric tons-force). The large size and estimated strength of this animal appears to have allowed it to include a wide range of prey in its diet, making it an

apex predator An apex predator, also known as a top predator or superpredator, is a predator at the top of a food chain, without natural predators of its own. Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the hig ...

in its ecosystem. As an adult, it would have preyed upon large to very large vertebrates such as the

xenarthra Xenarthra (; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a superorder and major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and ...

ns and notoungulates present, with no real competition from sympatric, smaller, carnivores. Researchers have proposed that the large size of ''Purussaurus'', though offering many advantages, may also have led to its vulnerability. The constantly changing environment on a large geological scale may have reduced its long-term survival, favoring smaller species more resilient to ecological shifts. In other words, it was over-specialised and couldn't survive when its habitat changed, unlike smaller related species of caiman. The skeletal anatomy of ''P. mirandai'' shows some adaptations for more upright limb orientation or weight support. Unlike all other members of the crown Crocodylia, which have two sacrals, ''P. mirandai'' have three. The

teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

vary between the three

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of ''Purussaurus'', but are always around 50 mm (2 in) long and curve slightly backwards. They have small ridges along two of the edges which resemble those in ziphodonts. This indicates that ''Purussaurus'' hunted large vertebrates, as these ridges are used for puncturing and holding on to flesh. The teeth are slightly flattened at the top and are roughly conical, which means that they would have been unlikely to break on impact with a thick bone. Teeth at the anterior are taller and more pointed, whereas those at the posterior are lower and more rounded. ''Purussaurus'' is one of the largest known

crocodyliformes Crocodyliformes is a clade of crurotarsan archosaurs, the group often traditionally referred to as "crocodilians". They are the first members of Crocodylomorpha to possess many of the features that define later relatives. They are the only pseu ...

ever to have existed. Three other extinct crocodyliformes, '' Sarcosuchus'', ''

Deinosuchus ''Deinosuchus'' is an extinct genus of eusuchian, either an Alligatoroidea, alligatoroid Crocodilia, crocodilian or a stem-group crocodilian, which lived during the Late Cretaceous around . The first remains were discovered in North Carolina ...

'', and '' Rhamphosuchus'' had similar body sizes. ''Sarcosuchus'' and ''Deinosuchus'' had similar proportions, but both were

geological 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 s ...

ly much older, dating from the Early and Late

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 ...

, respectively. One study also indicates that ''Purussaurus'' may have been heavier than either ''Sarcosuchus'' or ''Deinosuchus,'' as it had a much broader, shorter snout and this would require a thicker, stronger neck to support the larger head. '' Rhamphosuchus'' lived around the same time as ''Purussaurus'', but was slightly smaller, had a more gharial-like snout and lived in

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

. During the summer of 2005, a Franco-Peruvian expedition (the Fitzcarrald expedition) found new

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 ...

s of ''Purussaurus'' in the Peruvian Amazon (600 km from

Lima Lima ( ; ), founded in 1535 as the Ciudad de los Reyes (, Spanish for "City of Biblical Magi, Kings"), is the capital and largest city of Peru. It is located in the valleys of the Chillón River, Chillón, Rímac River, Rímac and Lurín Rive ...

). Analysis of a biomechanical model of the skull of ''Purussaurus'' indicated that it was capable of performing the "

death roll In a keel boat, a death roll is the act of broaching to windward, putting the spinnaker pole into the water and causing a crash-jibe of the boom and mainsail, which sweep across the deck and plunge down into the water. The death roll often resu ...

" maneuver used by extant crocodilians to subdue and dismember their prey. All sense organs (eyes, ears, nostrils) were at the very top of the head, indicating that ''Purussaurus'' was an ambush predator like many modern caimans.

Paleoecology

The probable diet of ''Purussaurus'' likely included the extinct turtle '' Stupendemys'', crocodilians including '' Charactosuchus'', '' Gryposuchus'', and '' Mourasuchus'', ''

Anhinga The anhinga (; ''Anhinga anhinga''), sometimes called snakebird, darter, American darter, or water turkey, is a water bird of the warmer parts of the Americas. The word ''anhinga'' comes from ''a'ñinga'' in the Brazilian Tupi language and means ...

'' birds, and mammals including:

sloth Sloths are a Neotropical realm, Neotropical group of xenarthran mammals constituting the suborder Folivora, including the extant Arboreal locomotion, arboreal tree sloths and extinct terrestrial ground sloths. Noted for their slowness of move ...

s, bats, rodents related to the modern

capybara The capybara or greater capybara (''Hydrochoerus hydrochaeris'') is the largest living rodent, native to South America. It is a member of the genus '' Hydrochoerus''. The only other extant member is the lesser capybara (''Hydrochoerus isthmi ...

('' Josephoartigasia'') weighing up to 700 kilograms (1540 lb), the primate '' Stirtonia'', and river dolphins. Rivers, floodplains, and lake environments were present. Marine and freshwater fish, turtles, crocodilians, and terrestrial and aquatic mammals are associated with Venezuelan ''P. mirandai''. Its environment is described as tropical and coastal. The earlier Colombian ''P. neivensis'' lived alongside a massive variety of fauna, including astrapotheres like '' Granastrapotherium'' and '' Xenastrapotherium'', the early species of ''Mourasuchus'' and ''Gryposuchus'', and the terrestrial crocodyliform '' Langstonia''. Bite marks on the tibia of a phorusrhacid from this locality are consistent with a caimanine, possibly a young individual of ''Purussaurus''. This fauna dates from 13 million years ago, in the

Laventan The Laventan () age is a period of geologic time (13.8 to 11.8 Ma) within the Middle Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Colloncuran and precedes the Mayoan age. ...

stage of the Late Miocene.

Etymology

The genus was named for the

Purus River The Purus River (Portuguese: ''Rio Purus''; Spanish: ''Río Purús'') is a tributary of the Amazon River in South America. Its drainage basin is , and the mean annual discharge is . The river shares its name with the Alto Purús National Park a ...

where its fossils were first found.

Distribution

Fossils of ''Purussaurus'' have been found in:''Purussaurus''
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 ;Miocene * Solimões Formation,

* Honda Group and Castilletes Formation,

* Culebra Formation,

* Fitzcarrald Arch and

Pebas Formation The Pebas Formation is a stratigraphic unit#Lithostratigraphic units, lithostratigraphic unit of Miocene age, found in western Amazon rainforest, Amazonia. The geological formation, formation extends over , including parts of Brazil, Peru, Ecuador ...

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

* Urumaco Formation, Urumaco and Socorro Formation,

* Ituzaingó Formation,

References

External links

Tetrapod Zoology post on ''Purussaurus''
*

*
Article about ''Purussaurus'' on ''DinosaurusBlog''
{{Taxonbar, from=Q133296, from2=Q1241636, from3=Q48789986 Jacarea Prehistoric pseudosuchian genera Miocene crocodylomorphs Miocene reptiles of South America Miocene reptiles of North America Montehermosan Huayquerian Chasicoan Mayoan Laventan Colloncuran Friasian Neogene Brazil Neogene Colombia Neogene Panama Neogene Peru Neogene Venezuela Fossils of Brazil Fossils of Colombia Honda Group, Colombia Fossils of Panama Fossils of Peru Fossils of Venezuela Fossil taxa described in 1892 Taxa named by João Barbosa Rodrigues Apex predators