Notosuchia

Notosuchia Temporal range: Early Cretaceous – Middle Miocene, 110–11 Ma PreЄ Є O S D C P T J K Pg N
Mounted skeleton of the notosuchian Simosuchus clarki in the Royal Ontario Museum
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	Crocodylomorpha
Clade:	Metasuchia
Suborder:	†Notosuchia Gasparini, 1971
Families
†Notosuchidae †Chimaerasuchidae †Comahuesuchidae †Candidodontidae †Sphagesauridae †Sebecosuchia

Notosuchia is a suborder of primarily Gondwanan mesoeucrocodylian crocodylomorphs that lived during the Cretaceous. 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 (Chimaerasuchus), omnivory (Simosuchus), and terrestrial hypercarnivory (Baurusuchus). 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 (Armadillosuchus), and possibly fleshy cheeks and pig-like snouts (Notosuchus). The suborder was first named in 1971 by Zulma Gasparini and has since undergone many phylogenetic revisions.^[1]

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:

Genus	Age	Location	Unit	Notes	Images
Adamantinasuchus	Turonian - Santonian	Brazil	Adamantina Formation	A carnivore with a very short, high skull and large eye sockets
Anatosuchus	Aptian - Albian	Niger	Tegama Group	A small notosuchian under 1 metre (3.3 ft) long with a duck-like snout
Araripesuchus	Albian - Maastrichtian	Madagascar  Niger  Brazil  Argentina	Maevarano Formation Echkar Formation Santana Formation Candeleros Formation	Five species are known, the most of any notosuchian
Armadillosuchus	Turonian - Santonian	Brazil	Adamantina Formation	A sphagesaurid with armadillo-like armor shields.
Baurusuchus	Turonian	Brazil	Adamantina Formation	A large hypercarnivore 3.5 to 4 metres (11 to 13 ft) in length
Caipirasuchus	Turonian – Santonian	Brazil	Adamantina Formation
Campinasuchus	Turonian – Santonian	Brazil	Adamantina Formation
Candidodon	Albian	Brazil	Itapecuru Formation
Chimaerasuchus	Aptian - Albian	China	Wulong Formation	The first notosuchian found with heterodont teeth, thought to be a herbivore
Comahuesuchus	Santonian	Argentina	Bajo de la Carpa Formation
Cynodontosuchus	Coniacian – Santonian	Argentina	Bajo de la Carpa Formation Pichi Picun Leufu Formation
Libycosuchus	Cenomanian	Egypt  Nigeria	Bahariya formation
Malawisuchus	Early Cretaceous	Malawi		A possible burrower that could move its jaw back and forth while eating
Mariliasuchus	Campanian - Maastrichtian	Brazil	Adamantina Formation
Morrinhosuchus	Turonian - Santonian	Brazil	Adamantina Formation
Notosuchus	Coniacian - Santonian	Argentina	Bajo de la Carpa Formation	A notosuchian that may have had a pig-like snout
Pakasuchus	Albian	Tanzania		A notosuchian with very complex, mammal-like heterodont teeth.
Pissarrachampsa	Campanian – Maastrichtian	Brazil	Vale do Rio do Peixe Formation
Simosuchus	Maastrichtian	Madagascar		A broad-snouted omnivore with clove-shaped teeth
Sphagesaurus	Late Cretaceous	Brazil	Adamantina Formation	An omnivorous notosuchian
Stratiotosuchus	Turonian – Santonian	Brazil	Adamantina Formation
Uruguaysuchus	Santonian - Campanian	Uruguay
Wargosuchus	Santonian	Argentina	Bajo de la Carpa Formation
Yacarerani	Turonian - Santonian	Bolivia		A notosuchian with rabbit-like incisors found in association with a probable nest

Phylogeny

Cladograms of Notosuchia

Ortega et al., 2000[2] Notosuchia  Notosuchus Libycosuchus Baurusuchus Iberosuchus Sebecus Itaborai crocodile Bretesuchus

Pol, 2003[3] Notosuchia  Uruguaysuchus Simosuchus Malawisuchus Candidodon Notosuchus Comahuesuchus Chimaerasuchus Sphagesaurus  Sebecosuchia  Baurusuchus Bretesuchus Iberosuchus

Larsson and Sues, 2007[4] Metasuchia   Notosuchia Notosuchus Malawisuchus Araripesuchus Baurusuchus Neosuchia  Sebecia  Pabwehshi  Sebecidae  Sebecus Bretesuchus Peirosauridae   Taxa previously assigned to Notosuchia

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.^[2] The definition of Notosuchia by Sereno et al. (2001) is similar to that of Ziphosuchia as it includes within it Sebecosuchia. Pol (2003) also includes Sebecosuchia within Notosuchia.^[3] More recently, a phylogenetic analysis by Larsson and Sues (2007) resulted in the naming of a new clade, Sebecia, to include sebecids and peirosaurids.^[4] 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. (2012) 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 (2010), Andrade et al. (2011), Montefeltro et al. (2011), Larsson and Sues (2007), and Novas et al. (2009), and 34 characters were noval, resulting in a matrix that includes 109 crocodyliforms and outgroup taxa which are scored based on 412 morphological traits.^[5]

Notosuchia

Uruguaysuchidae Araripesuchus tsangatsangana Anatosuchus Araripesuchus wegeneri Araripesuchus buitreraensis Araripesuchus gomesii Araripesuchus patagonicus Uruguaysuchus Stolokrosuchus Mahajangasuchidae Kaprosuchus Mahajangasuchus Peirosauridae Hamadasuchus Gasparinisuchus Lomasuchus Montealtosuchus Uberabasuchus Candidodon Ziphosuchia Libycosuchus Simosuchus Malawisuchus Pakasuchus Morrinhosuchus Notosuchus Coringasuchus Labidiosuchus Mariliasuchus Sphagesauridae Adamantinasuchus Yacarerani Caipirasuchus stenognathus Caipirasuchus paulistanus Caipirasuchus montealtensis Sphagesaurus Armadillosuchus Caryonosuchus Chimaerasuchus Comahuesuchus Sebecosuchia Pabwehshi Baurusuchidae Cynodontosuchus Pissarrachampsa Stratiotosuchus Campinasuchus Baurusuchus albertoi Baurusuchus pachecoi Baurusuchus salgadoensis Bergisuchus Iberosuchus Sebecidae Lorosuchus Pehuenchesuchus Barinasuchus Ayllusuchus Bretesuchus Lumbrera form Langstonia Sebecus Zulmasuchus

References

1. Gasparini, Z. (1971). "Los Notosuchia del Cretácico de América del Sur como un nuevo Infraorden de los Mesosuchia (Crocodilia)". Ameghiniana. 8: 83–103.
2. Ortega, F. Z.; Buscalioni, A. D.; Calvo, J. O. (2000). "A new species of Araripesuchus (Crocodylomorpha, Mesoeucrocodylia) from the Lower Cretaceous of Patagonia (Argentina)". Journal of Vertebrate Paleontology. 20 (1): 57–76. doi:10.1671/0272-4634(2000)020[0057:ANSOAC]2.0.CO;2.
3. Pol, D. (2003). "New Remains of Sphagesaurus huenei (Crocodylomorpha: Mesoeucrocodylia) from the Late Cretaceous of Brazil". Journal of Vertebrate Paleontology. 23 (4): 817–831. doi:10.1671/A1015-7.
4. Larsson, H. C. E.; Sues, H.-D. (2007). "Cranial osteology and phylogenetic relationships of Hamadasuchus rebouli (Crocodyliformes: Mesoeucrocodylia) from the Cretaceous of Morocco". Zoological Journal of the Linnean Society. 149 (4): 533–567. doi:10.1111/j.1096-3642.2007.00271.x.
5. Pol, D.; Nascimento, P. M.; Carvalho, A. B.; Riccomini, C.; Pires-Domingues, R. A.; Zaher, H. (2014). "A New Notosuchian from the Late Cretaceous of Brazil and the Phylogeny of Advanced Notosuchians". PLoS ONE. 9 (4): e93105. doi:10.1371/journal.pone.0093105. PMC 3973723. PMID 24695105.