Candidodontidae is a 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 notosuchia

Notosuchia

Notosuchia is a suborder of primarily Gondwanan mesoeucrocodylian crocodylomorphs that lived during the Cretaceous. Fossils have been found from South America, Africa, and Asia...

n crocodyliforms. It was originally used in 2002 as a name for a 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...

 that includes the genera

Genera

Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...

 Araripesuchus

Araripesuchus

Araripesuchus is a genus of extinct crocodyliform whose species existed during the Cretaceous period of the late Mesozoic era some 125 to 65 million years ago. They are generally considered to be notosuchians , characterized by their varied teeth types and distinct skull elements...

, Candidodon

Candidodon

Candidodon is an extinct genus of notosuchian mesoeucrocodylian. Fossils have been found of Early Cretaceous age from Brazil. The genus is characterized by a particularly elongate pair of choanae in its palate. It has been named the type genus of the family Candidodontidae, first constructed in 2004...

, and Malawisuchus

Malawisuchus

Malawisuchus is an extinct genus of notosuchian mesoeucrocodylian from the Early Cretaceous of Malawi. It was described in 1997 by Elizabeth Gomani as a member of the family Notosuchidae. The type species is M. mwakasyungutiensis, referring to Mwakasyunguti, the area of northern Malawi where it...

. Later in 2004 the family was formally defined as a node-based taxon including Candidodon itapecuruense and Mariliasuchus amarali

Mariliasuchus

Mariliasuchus is an extinct genus of Late Cretaceous notosuchian mesoeucrocodylian found near Marilia, Brazil. It was described in 1999 by Brazilian palaeontologists Ismar de Souza Carvalho and Reinaldo J. Bertini....

. A 2009 study redefined Candidodontidae as a stem-based taxon which included Candidodon, Malawisuchus, and possibly Mariliasuchus.

Phylogenetics

The first formal definition of the family does not fit well with many phylogenetic studies of notosuchians that place Candidodon and Mariliasuchus far apart. If this definition were to be used, Candidodontidae would include the last common ancestor of Candidodon and Mariliasuchus and all of its descendants. According to these studies, these descendants would include many other genera and families, some of which were named before Candidodontidae and thus would have priority over it.

A new definition was given in 2009 in which Candidodontidae was considered a stem-based taxon. Under this definition, Candidodontidae includes all taxa more closely related to Candidodon itapecuruensis than to Notosuchus terrestris

Notosuchus

Notosuchus is an extinct genus of South American notosuchian crocodylomorph. It was terrestrial, living approximately 85 million years ago in the Coniacian or Santonian stages of the Late Cretaceous. Remains have been found in the Bajo de la Carpa Formation in Patagonia, Argentina. First named in...

, Uruguaysuchus aznarezi

Uruguaysuchus

Uruguaysuchus is an extinct genus of crocodylomorph from the Late Cretaceous of Uruguay. It was related to Simosuchus and Malawisuchus.-Sources:* A Pictorial Guide to Fossils by Gerard Ramon Case...

, Comahuesuchus brachybuccalis

Comahuesuchus

Comahuesuchus is an extinct genus of notosuchian crocodylomorph from the Late Cretaceous of Argentina. It was described by palaeontologist José Bonaparte in 1991.The type species is C. brachybuccalis.- Material :...

, Sphagesaurus huenei

Sphagesaurus

Sphagesaurus is an extinct genus of notosuchian crocodylomorph from the Late Cretaceous of Brazil.-Species and discovery:The type species S. huenei, was discovered in 1950 by Price, with the both the genus and species named from two isolated teeth. More recently a nearly complete skull of S...

, Baurusuchus pachecoi

Baurusuchus

Baurusuchus is an extinct genus of baurusuchid mesoeucrocodylian from the Late Cretaceous of Brazil. It was a terrestrial predator and scavenger, about 3.5 to 4 meters long. Baurusuchus lived during the Turonian to Santonian stages of the Late Cretaceous Period, in Adamantina Formation, Brazil...

, and Crocodylus niloticus. The number of species that are less closely related to these taxa are called specifiers, and were used to insure that Candidodontidae did not become overly inclusive if Candidodon was placed in a different phylogenetic position in the future. According to the 2009 study, Candidodontidae includes Candidodon, Malawisuchus, and possibly Mariliasuchus.

Description

Members of Candidodontidae can be defined on the basis of synapomorphies, characteristics shared between taxa and present in their most recent common ancestor. When the family was first defined, several synapomorphies were used to diagnose it. For example, one synapomorphy was the large size of the supratemporal fenestrae, two holes that occupy most of the surface of the skull roof

Skull roof

The skull roof , or the roofing bones of the skull are a set of bones covering the brain, eyes and nostrils in bony fishes and all land living vertebrates. The bones are derived from dermal bone, hence the alternative name dermatocranium...

. Another synapomorphy was the similar size and shape of the postcaniniform teeth, those that are behind the caniniforms and in front of the molariforms

Molar (tooth)

Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....

. The distance between the front of the eye sockets and the tip of the snout is greater than or equal to the distance between the front of the eye sockets and the back of the skull. Inside the skull, the internal nares

Nasal cavity

The nasal cavity is a large air filled space above and behind the nose in the middle of the face.- Function :The nasal cavity conditions the air to be received by the other areas of the respiratory tract...

 are not separated from one another.

The 2009 definition was from a study that focused on the teeth of notosuchians. Several features of the teeth of candidodontids were identified. These include a constricted crown base, a bulbous shape to the tooth, and several distinctive cusps

Cusp (dentistry)

A cusp is an occlusal or incisal eminence on a tooth.Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps...

. In candidodontids, namely Candidodon and Malawisuchus, there is a main cusp and several smaller cusps surrounding it.