Hylaeochampsidae is an extinct family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of basal

Basal (phylogenetics)

In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...

 eusuchia

Eusuchia

Eusuchia is a clade of crocodylomorphs that first appears in the Early Cretaceous with Hylaeochampsa. All living crocodilian species are eusuchians, as are many extinct forms.-Description:...

n crocodylomorphs

Crocodylomorpha

The Crocodylomorpha are an important group of archosaurs that include the crocodilians and their extinct relatives.During Mesozoic and early Tertiary times the Crocodylomorpha were far more diverse than they are now. Triassic forms were small, lightly built, active terrestrial animals. These were...

 thought to be closely related to the order Crocodylia. It was first constructed by Charles William Andrews

Charles William Andrews

Charles William Andrews F.R.S., was a British palaeontologist whose career as a vertebrate paleontologist, both as a curator and in the field, was spent in the services of the British Museum, Department of Geology.-Biography:...

 in 1913 to include just one member: Hylaeochampsa

Hylaeochampsa

Hylaeochampsa is an extinct genus of eusuchian crocodylomorph. It is known only from a partial skull recovered from Barremian-age rocks of the Lower Cretaceous Vectis Formation of the Isle of Wight. This skull, BMNH R 177, is short and wide, with a eusuchian-like palate and inferred enlarged...

. However, a new genus named Iharkutosuchus

Iharkutosuchus

Iharkutosuchus is an extinct genus of basal eusuchian crocodyliform. It fossils have been found in the Santonian-age Upper Cretaceous Csehbánya Formation in the Bakony Mountains of western Hungary...

was described in 2007 and was found to be a sister taxon of Hylaeochampsa, and thus a member of the family Hylaeochampsidae. The genus Heterosuchus

Heterosuchus

Heterosuchus is an extinct genus of crocodylomorph that may have been an eusuchian. It is known only from neck and back vertebrae recovered from Early Cretaceous-age rocks of the Hastings Beds Heterosuchus is an extinct genus of crocodylomorph that may have been an eusuchian. It is known only...

, named in 1887, may also be a member of the family. However, it is likely to be synonymous

Synonym (taxonomy)

In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...

 with Hylaeochampsa and has been considered a nomen dubium

Nomen dubium

In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...

by James M. Clark and Mark Norell. Clark and Norell also claimed that there is no evidence to suggest that the two genera form a true clade

Clade

A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...

 distinct from other eusuchians, because remains associated with Heterosuchus are to fragmentary to show any clear pylogenetic relationship.

The family existed during the Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 period in what is now Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

. Hylaeochampsa and its possible synonym Heterosuchus have both been found from the Vectis Formation

Vectis Formation

The Vectis Formation is a geological formation on the Isle of Wight, England whose strata date back to the Early Cretaceous . The Vectis Formation is composed of three geological members: the Shepherds Chine member, the Barnes High Sandstone member, and the Cowleaze Chine member...

 of the Isle of Wight

Isle of Wight

The Isle of Wight is a county and the largest island of England, located in the English Channel, on average about 2–4 miles off the south coast of the county of Hampshire, separated from the mainland by a strait called the Solent...

 in England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

, dating back to the Barremian

Barremian

The Barremian is an age in the geologic timescale between 130.0 ± 1.5 Ma and 125.0 ± 1.0 Ma). It is a subdivision of the Early Cretaceous epoch...

 stage of the Early Cretaceous

Early Cretaceous

The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...

. Specimens of Iharkutosuchus have been found from the Csehbánya Formation

Csehbánya Formation

The Csehbánya Formation is a geological formation in Hungary whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.-Vertebrate paleofauna:...

 in western Hungary

Hungary

Hungary , officially the Republic of Hungary , is a landlocked country in Central Europe. It is situated in the Carpathian Basin and is bordered by Slovakia to the north, Ukraine and Romania to the east, Serbia and Croatia to the south, Slovenia to the southwest and Austria to the west. The...

, which was deposited during the Santonian

Santonian

The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous epoch or Upper Cretaceous series. It spans the time between 85.8 ± 0.7 mya and 83.5 ± 0.7 mya...

 stage of the Late Cretaceous

Late Cretaceous

The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...

. All hylaeochampsids had highly brevirostrine snouts and exhibited heterodonty, with large teeth concentrated posteriorly that were most likely adapted to crushing. In Iharkutosuchus these teeth were even multicusped. This is often characteristic of mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s but is highly unusual for a crocodylomorph, and suggests that the animal may have been herbivorous.

External links

• Hylaeochampsidae in the Paleobiology Database
  Paleobiology Database
  ' is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms.-History:The Paleobiology Database was founded in 2000. It has been funded by the National Science Foundation and the Australian Research Council...