''Araripesuchus'' is a genus of

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 ...

crocodyliform Crocodyliformes is a clade of Crurotarsi, 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 ...

that existed during the

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 ...

period of the late

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

era some 125 to 66 million years ago. ''Araripesuchus'' is generally considered to be a

notosuchia Notosuchia is a clade of primarily Gondwanan mesoeucrocodylian Crocodylomorpha, crocodylomorphs that lived during the Jurassic and Cretaceous. Some phylogeny, phylogenies recover Sebecosuchia as a clade within Notosuchia, others as a sister group ...

n (belonging to the

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

Mesoeucrocodylia Mesoeucrocodylia is the clade that includes Eusuchia and crocodyliforms formerly placed in the paraphyletic group Mesosuchia. The group appeared during the Early Jurassic, and continues to the present day. Diagnosis It was long known that Me ...

), characterized by the varied teeth types and distinct skull elements. Seven species have been referred to ''Araripesuchus'', though it has been argued that the phylogenetic position of this genus is uncertain, and that taxonomic revision is required.

Description

''A. wegeneri'' is estimated to reach long while ''A. rattoides'' is estimated to reach up to . ''Araripesuchus'' can be distinguished by their laterally bulged edges of the snout, with the bulge being the most prominent around the area of an enlarged

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

ry tooth. The snout and

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammals h ...

are also smoother than that of most crocodyliforms, without

foramina In anatomy and osteology, a foramen (; : foramina, or foramens ; ) is an opening or enclosed gap within the dense connective tissue (bones and deep fasciae) of extant and extinct amniote animals, typically to allow passage of nerves, arter ...

or the typical rugose texture. There are seven valid species within this genus, all with slightly differing maxillary or dentary structure. ''A. gomesii, A. wegeneri'' and ''A. tsangatsangana'' all have a mild concavity of the external

alveolar Alveolus (; pl. alveoli, adj. alveolar) is a general anatomical term for a concave cavity or pit. Uses in anatomy and zoology * Pulmonary alveolus, an air sac in the lungs ** Alveolar cell or pneumocyte ** Alveolar duct ** Alveolar macrophage * M ...

margin of the premaxilla as viewed from the ventral surface; ''A. rattoides'' may also have this feature, although this part of its skull is not known, as the dentary suggests that this would be the case. ''A. rattoides'' also had the distinctive feature of a highly enlarged and forward-pointing first dentary tooth referred to as an incisiform, resembling the elongated incisors found in

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

s (hence the specific epithet). All species of ''Araripesuchus'' had relatively large

orbits In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an physical body, object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an satellite, artificia ...

and hence

eye An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

s. They also had thin

osteoderm Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amph ...

s that covered the entire body, multiple rows of them across the back and paired dorsal ones along the tail. Each side of the tail also had a single row of osteoderms, and there were paired ventral osteoderms across most of the belly and underside as well. The osteoderms were not strongly keeled, which, along with the long limb bones and shoulder, hip and ankle joints that suggest upright posture, indicate that ''Araripesuchus'' was probably more active on land than on water.

Discovery and history

The name of the genus was coined in 1959 with the description 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 ...

''Araripesuchus gomesii'', a

n crocodylian from the famed

Santana Group The Santana Group is a geologic group, formerly included as the middle part of the Araripe Group, in the Araripe Basin of northeastern Brazil. The group comprises the Crato, Ipubi and Romualdo Formations and is dated to the Aptian to Albian stag ...

of the

Araripe Basin The Araripe Basin () is a rift basin covering about ,Neto et al., 2013, p.1 in Ceará, Piauí and Pernambuco states of northeastern Brazil. It is bounded by the Patos and Pernambuco lineaments, and is situated east of the Parnaíba Basin, south ...

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 ...

. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

used to describe the genus, 423-R is currently in the care of the Divisão de Mineralogia e Geologia do Departamento Nacional da Produção Mineral in

Rio de Janeiro Rio de Janeiro, or simply Rio, is the capital of the Rio de Janeiro (state), state of Rio de Janeiro. It is the List of cities in Brazil by population, second-most-populous city in Brazil (after São Paulo) and the Largest cities in the America ...

. 423-R consists of a single skull articulating with part of a lower jaw. A more complete specimen, AMNH 24450 is held by the

American Museum of Natural History The American Museum of Natural History (AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. Located in Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 21 interconn ...

. A second species, ''A. wegeneri'' was described in 1981. This species was discovered from

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

deposits of

Niger Niger, officially the Republic of the Niger, is a landlocked country in West Africa. It is a unitary state Geography of Niger#Political geography, bordered by Libya to the Libya–Niger border, north-east, Chad to the Chad–Niger border, east ...

on the

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 ...

n continent, as opposed to the

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 ...

n paleodistribution of the other species in the genus. The type specimen for the species, GDF-700 consisting of a few, fragmentary jaw elements, reside at the

Museum 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 ...

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 ...

. The holotype's fragmentary nature meant that its placement in the genus was disputed until more remains were found in 2009 by Sereno and Larsson; these, along with the specimens of ''A. tsangatsangana,'' confirmed its place. ''Araripesuchus patagonicus'' was described from a

patagonia Patagonia () is a geographical region that includes parts of Argentina and Chile at the southern end of South America. The region includes the southern section of the Andes mountain chain with lakes, fjords, temperate rainforests, and glaciers ...

n specimen (MUC-PV 269) in 2000. Another species to be assigned to the genus, was '' Araripesuchus buitreraensis'', described in 2005. This species was described from a single skull (MPCA-PV 235) retrieved from

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

deposits in what is now

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 ...

. At 130 millimeters, the skull is the largest ''Araripesuchus'' specimen discovered to date. A fifth species, ''Araripesuchus tsangatsangana'' was described in 2006. This species' type specimen was discovered from latest Late Cretaceous deposits from the African island of

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

. Analysis of this specimen solidifies the position of ''A. wegneri'' as a member of the genus. ''A. tsangatsangana'' is the geologically youngest known of this genus. The sixth species, ''A. rattoides'', was found in the

Kem Kem Beds The Kem Kem Group (commonly known as the Kem Kem beds) is a geological 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 geological formations ...

of the

Sahara The Sahara (, ) is a desert spanning across North Africa. With an area of , it is the largest hot desert in the world and the list of deserts by area, third-largest desert overall, smaller only than the deserts of Antarctica and the northern Ar ...

in a similar location to the specimens of ''A. wegeneri'' found by Sereno and Larsson, and is known only from parts of dentary bones, up to the fourteenth alveolus. It was described in the same paper as '' Kaprosuchus'', ''

Laganosuchus ''Laganosuchus'' is an extinct genus of stomatosuchid crocodyliform. Fossils have been found from Niger and Morocco and date back to the Upper Cretaceous. Discovery The name means "pancake crocodile" from the Greek , ("pancake") and , ("croc ...

'' and '' Anatosuchus''; the four were therefore popularized by the authors as 'RatCroc', 'BoarCroc', 'PancakeCroc' and 'DuckCroc' respectively.

Classification

As of 2024, seven species were recognized within the genus ''Araripesuchus'': ''A. gomesii'' (

), ''A. buitreraensis'', ''A. manzanensis'', ''A. patagonicus'', ''A. rattoides'', ''A. tsangatsangana'' and ''A. wegeneri''. The placement of the first African species discovered, ''A. wegeneri'', was questioned for a while by various authors. Ortega et al. argued for the assignment of the errant species to another genus based on phylogenetic analysis Further analysis, combined with the discovery of the second African species ''A. tsangatsangana'' has shed more light on the placement of ''A. wegeneri'' within the genus. When analyzed together, the African species support the inclusion of all five first described species into the same genus. The genus was originally assigned by Price to the family

Uruguaysuchidae Uruguaysuchidae is a family of notosuchian crocodyliforms that lived in South America and Africa during the Cretaceous period. It was formally defined under the PhyloCode in 2024 as "the most inclusive clade containing ''Uruguaysuchus aznarezi'' ...

in the original 1959 description. This classification was followed by Buffetaut in 1981 with the description of ''A. wegeneri'' also within the same family. However, in their 2000 description of ''A. patagonicus'', Ortega et al. avoided placing the species within the family. Instead, it was simply noted that '' Uruguaysuchus'' was a possible close relative of the genus. Ortega et al. and several other studies place ''Araripesuchus'' outside Notosuchia. In some phylogenetic analyses, it is placed closer to the clade

Neosuchia Neosuchia is a clade within Mesoeucrocodylia that includes all modern extant crocodilians and their closest fossil relatives. It is defined as the most inclusive clade containing all Crocodylomorpha, crocodylomorphs more closely related to ''Croc ...

, which includes modern crocodilians. In most recent analyses, however, ''Araripesuchus'' is placed as a basal notosuchian. The phylogenetic analysis of Soto et al. (2011) joined ''Araripesuchus'' with ''Uruguaysuchus'', reinstating the family Uruguaysuchidae. This family was found to be the most basal group of Notosuchia. Below is a cladogram from the analysis: Araripesuchus rattoides

However, recent phylogenetic analyses placed ''A. wegeneri'' as a sister taxon of '' Anatosuchus'', questioning the monophyly of the genus. Lumping all species into one genus would lead to ''Uruguaysuchus'' taking priority, rendering ''Araripesuchus'' a junior synonym of ''Uruguaysuchus''.

Paleoecology

''Araripesuchus'' remains have been recovered from the continents of

and

suggesting a

Gondwana Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...

n origin for the evolution of the genus. At around the time of ''Araripesuchus existence, South America and Africa were physically adjacent to each other. The various species evolved from the same stock in the general area, radiating outward from a yet-unidentified origin point. The presence of specimens from

further strengthens this

evolutionary radiation An evolutionary radiation is an increase in taxonomic diversity that is caused by elevated rates of speciation, that may or may not be associated with an increase in morphological disparity. A significantly large and diverse radiation within ...

model.

References

External links

{{Taxonbar, from=Q776081 Notosuchia Terrestrial crocodylomorphs Early Cretaceous crocodylomorphs of South America Late Cretaceous crocodylomorphs of South America Cretaceous Argentina Fossils of Argentina Cretaceous Brazil Fossils of Brazil Early Cretaceous crocodylomorphs of Africa Late Cretaceous crocodylomorphs of Africa Crocodylomorphs of Madagascar Maevarano fauna Cretaceous Cameroon Fossils of Cameroon Cretaceous Malawi Fossils of Malawi Cretaceous Morocco Fossils of Morocco Cretaceous Niger Fossils of Niger Cretaceous Tunisia Fossils of Tunisia Fossil taxa described in 1959 Prehistoric pseudosuchian genera