Stagonolepis

Stagonolepis Temporal range:
Stagonolepis
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Archosauria
Clade:	Pseudosuchia
Order:	†Aetosauria
Family:	†Stagonolepididae
Genus:	†Stagonolepis Agassiz, 1844
Species
†S. robertsoni Agassiz, 1844 (type) †S. wellesi Murray & Long, 1989 †S. olenkae Sulej, 2010 †?S. scaglia Casamiquela, 1960 †?S. subsulcatus Zacarias, 1982
Synonyms
?Aetosauroides Casamiquela, 1960

Stagonolepis is an extinct genus of archosaur reptile belonging to the aetosaur order. It was about 3 metres (10 ft) long.

Model at the Museum of Evolution Warsaw

An aetosaur, Stagonolepis was a quadrupedal animal covered in thick armoured scales that ran down the length of the its body. A slow-moving browser, it would have used this heavy body armour to repel attacks from contemporary thecodont carnivores. Stagonolepis had a very small head for its size; it was only 25 centimetres (10 in), accounting for less than 10% of the total body length. It had no teeth in the front of its jaws, but instead had a beak-like tip that arched upwards. This would have allowed it to uproot plants in a similar manner to a modern pig. The peg-like teeth at the back of its mouth would have been suitable for chewing tough vegetation, including horsetails, ferns, and the newly evolved cycads.

The Krasiejów museum in Poland, near where remains of Stagonolepis and other Triassic tetrapods have been found.

Fossil remains of the animal have been found in Scotland, South America, and Poland. The genus Aetosauroides from South America has been considered a junior synonym of Stagonolepis by some paleontologists. Two species of Aetosauroides were named, A. scagliai and A. subsulcatus. In 2002, Andrew B. Heckert and Spencer G. Lucas proposed that smaller specimens of both species belong to Stagonolepis robertsoni, and larger specimens to S. wellesi.