Goniopholididae is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

family of moderate-sized semi-aquatic

neosuchian 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 crocodylomorphs more closely related to ''Crocodylus nilotic ...

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 pse ...

. Their bodyplan and morphology are convergent on living

crocodilians Crocodilia (or Crocodylia, both ) is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 95 million years ago in the Late Cretaceous period (Cenomanian stage) and are the closest living re ...

. They lived across

Laurasia Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pan ...

(Asia, Europe and North America) between the Middle Jurassic (possibly Early Jurassic, see below) and the Late Cretaceous.

Description

Compared to modern crocodilians, goniopholidids are very unusual in several respects. They possessed two rows of rectangular, interlocking

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 amp ...

s like those of terrestrial crocodilymorphs like atoposaurids, that are relatively simple, do not extend far in their necks, as opposed to the ornate armours of modern crocodilians; likewise, unlike modern crocodilians but like many extinct forms like

phytosaur Phytosaurs (Φυτόσαυροι in greek) are an extinct group of large, mostly semiaquatic Late Triassic archosauriform reptiles. Phytosaurs belong to the order Phytosauria. Phytosauria and Phytosauridae are often considered to be equivalent g ...

s, they have ventral osteoderms as well. Their forelimbs are also proportionally very long, particularly in the humeri and wrist bones, being as long or longer than the hindlimbs, the opposite of the condition seen in modern crocodilians. Some like ''

Anteophthalmosuchus ''Anteophthalmosuchus'' (meaning "forward-pointing eye crocodile") is an extinct genus of goniopholidid mesoeucrocodylian from the Early Cretaceous of southern England, eastern Spain, and western Belgium. Discovery The holotype specimen of ''A ...

'' also have forwardly oriented eyes, as opposed to the dorsally oriented eyes seen in modern forms. These suggest multiple biomechanical differences from modern species. The paravertebral armour is composed of two rows of paired osteoderms with the lateral margins ventrally deflected and an anterior process for a ‘peg and groove’ articulation.

Ecology

Goniopholidids likely had a similar ecology to modern crocodilians as semi-aquatic ambush predators.

Evolutionary history

Goniopholidids have only been found in

(Asia, Europe and North America). The oldest possible member of the group is ''

Calsoyasuchus ''Calsoyasuchus'' (meaning " r. KyrilCalsoyas' crocodile") is a genus of crocodylomorph that lived in the Early Jurassic. Its fossilized remains were found in the Sinemurian-Pliensbachian-age Kayenta Formation on Navajo Nation land in Coconino ...

'' from the Early Jurassic of North America.Tykoski RS, Rowe TB, Ketcham RA, Colbert MW. 2002. ''Calsoyasuchus valliceps'', a new crocodyliform from the Early Jurassic Kayenta Formation of Arizona. ''Journal of Vertebrate Paleontology'' 22 (3): 593-611. However, its placement is disputed, with some studies recovering it as only distantly related to goniopholidids. The goniopholidids were present across Eurasia during the Middle Jurassic and were widespread in North America during the Late Jurassic and continued to remain prominent across Laurasia during the Early Cretaceous. Goniopolidids persisted into the late Upper Cretaceous in North America based on ''

Denazinosuchus ''Denazinosuchus'' is a genus of goniopholidid mesoeucrocodylian. Its fossils have been recovered from the Upper Cretaceous Fruitland Formation and Kirtland Formation (late Campanian-early Maastrichtian) of the San Juan Basin, New Mexico. It is ...

,'' from the

Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian s ...

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from ...

of New Mexico, which is only known from fragmentary remains, and has been disputed as a member of the group, as well as remains of an unnamed goniopholidid from the Campanian aged Aguja Formation of Texas.

Classification

The following

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

simplified after an analysis presented by Marco Brandalise de Andrade and colleagues in 2011.

References

{{Taxonbar, from=Q140153 Early Jurassic crocodylomorphs Early Cretaceous crocodylomorphs Sinemurian first appearances Maastrichtian extinctions Middle Jurassic crocodylomorphs Late Jurassic crocodylomorphs Late Cretaceous crocodylomorphs Prehistoric reptile families