Notosuchia


Notosuchia is a suborder of primarily Gondwanan mesoeucrocodylian crocodylomorphs that lived during the Jurassic and Cretaceous. Some phylogenies recover Sebecosuchia as a clade within Notosuchia, others as a sister group ; if Sebecosuchia is included within Notosuchia its existence is pushed into the Middle Miocene, about 11 million years ago. Fossils have been found from South America, Africa, Asia, and Europe. Notosuchia was a clade of terrestrial crocodilians that evolved a range of feeding behaviours, including herbivory, omnivory, and terrestrial hypercarnivory. It included many members with highly derived traits unusual for crocodylomorphs, including mammal-like teeth, flexible bands of shield-like body armor similar to those of armadillos, and possibly fleshy cheeks and pig-like snouts. The suborder was first named in 1971 by Zulma Gasparini and has since undergone many phylogenetic revisions.

Description

Notosuchians were generally small, with slender bodies and erect limbs. The most distinctive characteristics are usually seen in the skull. Notosuchian skulls are generally short and deep. While most are relatively narrow, some are very broad. Simosuchus has a broadened skull and jaw that resembles a pug, while Anatosuchus has a broad, flat snout like that of a duck.
The teeth vary greatly between different genera. Many have heterodont dentitions that vary in shape across the jaw. Often, there are large canine-like teeth protruding from the front of the mouth and broader molar-like teeth in the back. Some genera, such as Yacarerani and Pakasuchus, have extremely mammal-like teeth. Their molars are complex and multicuspid, and are able to occlude or fit with one another. Some forms such as Malawisuchus had jaw joints that enabled them to move the jaw back and forth in a shearing motion rather than just up and down.
A derived group of notosuchians, the baurusuchids differ considerably from other forms. They are very large in comparison to other notosuchians and are exclusively carnivorous. Baurusuchids have deep skulls and prominent canine-like teeth.

Classification

Taxonomy

Genera

The evolutionary interrelationships of Notosuchia are in flux, but the following genera are generally considered notosuchians:
GenusAgeLocationUnitNotesImages

Adamantinasuchus		Turonian - Santonian

Adamantina Formation
A carnivore with a very short, high skull and large eye sockets

Anatosuchus		Aptian - Albian

Tegama Group
A small notosuchian under long with a duck-like snout

Araripesuchus		Albian - Maastrichtian







Maevarano Formation

Echkar Formation

Santana Formation

Candeleros Formation
Six species are known, the most of any notosuchian

Armadillosuchus		Turonian - Santonian

Adamantina Formation		A sphagesaurid with armadillo-like armor shields.

Baurusuchus		Turonian

Adamantina Formation
A large hypercarnivore in length

Caipirasuchus		Turonian – Santonian

Adamantina Formation

Campinasuchus		Turonian – Santonian

Adamantina Formation

Candidodon		Albian

Itapecuru Formation

Chimaerasuchus		Aptian - Albian

Wulong Formation
The first notosuchian found with heterodont teeth, thought to be a herbivore

Comahuesuchus		Santonian

Bajo de la Carpa Formation

Cynodontosuchus		Coniacian – Santonian

Bajo de la Carpa Formation

Pichi Picun Leufu Formation

Libycosuchus		Cenomanian

Bahariya Formation
MalawisuchusEarly Cretaceous

A possible burrower that could move its jaw back and forth while eating

Mariliasuchus		Campanian - Maastrichtian

Adamantina Formation

Morrinhosuchus		Turonian - Santonian

Adamantina Formation

Notosuchus		Coniacian - Santonian

Bajo de la Carpa Formation
A notosuchian that may have had a pig-like snout

Pakasuchus		Albian
A notosuchian with very complex, mammal-like heterodont teeth.

Pissarrachampsa		Campanian – Maastrichtian

Vale do Rio do Peixe Formation

Razanandrongobe		Middle Jurassic

Sakaraha Formation
The earliest known member of the group.

Simosuchus		Maastrichtian
A broad-snouted omnivore with clove-shaped teeth

Sphagesaurus		Late Cretaceous

Adamantina Formation
An omnivorous notosuchian

Stratiotosuchus		Turonian – Santonian

Adamantina Formation

Uruguaysuchus		Santonian - Campanian

Wargosuchus		Santonian

Bajo de la Carpa Formation

Yacarerani		Turonian-Santonian
Cajones FormationA notosuchian with rabbit-like incisors found in association with a probable nest

Phylogeny

The clade Notosuchia has undergone many recent phylogenetic revisions. In 2000, Notosuchia was proposed to be one of two groups within the clade Ziphosuchia, the other being Sebecosuchia, which included deep snouted forms such as baurusuchids and sebecids. The definition of Notosuchia by Sereno et al. is similar to that of Ziphosuchia as it includes within it Sebecosuchia. Pol also includes Sebecosuchia within Notosuchia. More recently, a phylogenetic analysis by Larsson and Sues resulted in the naming of a new clade, Sebecia, to include sebecids and peirosaurids. Baurusuchidae was considered to be polyphyletic in this study, with Pabwehshi being a basal member of Sebecia and Baurusuchus being the sister taxon to the clade containing Neosuchia and Sebecia. Thus, Sebecosuchia was no longer within Notosuchia and not considered to be a true clade, while Notosuchia was found to be a basal clade of Metasuchia.
The following cladogram simplified after the most comprehensive analysis of notosuchians to date, presented by Pol et al. in 2014. It is based mainly on the data matrix published by Pol et al. which is itself a modified version of previous analyses. Thirty-one additional characters were added from other comprehensive analyses of notosuchians, e.g. Turner and Sertich, Andrade et al., Montefeltro et al., Larsson and Sues, and Novas et al., and 34 characters were noval, resulting in a matrix that includes 109 crocodyliforms and outgroup taxa which are scored based on 412 morphological traits.