''Chilenosuchus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

aetosaur Aetosaurs () are heavily armored reptiles belonging to the extinct order Aetosauria (; from Greek, (aetos, "eagle") and (, "lizard")). They were medium- to large-sized omnivorous or herbivorous pseudosuchians, part of the branch of archosaurs ...

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s have been found in the El Bordo Formation, in the

Antofagasta Region The Antofagasta Region ( es, Región de Antofagasta, ) is one of Chile's sixteen first-order administrative divisions. The second-largest region of Chile in area, it comprises three provinces, Antofagasta, El Loa and Tocopilla. It is bordered t ...

in northern

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

Description

The presence of ''Chilenosuchus'' in the beds that it was found in conflicts with the inferred age of the strata. Fossil plants and invertebrates suggest that it dates back to the late

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

Early Permian 01 or '01 may refer to: * The year 2001, or any year ending with 01 * The month of January * 1 (number) Music * '01 (Richard Müller album), 01'' (Richard Müller album), 2001 * 01 (Son of Dave album), ''01'' (Son of Dave album), 2000 * 01 (Urban ...

, yet ''Chilenosuchus'' is an aetosaur, and the first aetosaurs appeared in the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...

. Poor-quality photographs of the original specimen and an apparent lack of substantial material could not allow for definite classification of the specimen, so there was initially much controversy as to whether or not the fossil was from a true aetosaur. However, a reevaluation in 2003 upon the relocation of the material showed that it was in fact an aetosaur and that the strata were of Triassic age. Based on similarities in the armour plating, ''Chilenosuchus'' seems to be closely related to ''

Typothorax ''Typothorax'' is an extinct genus of typothoracine aetosaur that lived in the Late Triassic. Its remains have been found in North America. Two species are known: ''T. coccinarum'', the type species, and ''T. antiquum''. Description ''Typothor ...

''. It has been proposed to be a member of a recently devised clade,

Typothoracisinae Typothoracinae is a clade of aetosaurs within the subfamily Aetosaurinae. It was originally defined as a stem-based taxon including all aetosaurs closer to ''Typothorax'' than to ''Stagonolepis'' or ''Desmatosuchus''. This definition was later ex ...

, along with ''Typothorax'' and several other similar aetosaurs.Parker, W. G. (2003). Description of a new specimen of ''Desmatosuchus haplocerus'' from the Late Triassic of Northern Arizona. ''Unpublished MS thesis. Northern Arizona University, Flagstaff''. 315 p

/ref> However, because of the many other differences between it and other aetosaurs, the position of ''Chilenosuchus'' within

Stagonolepididae Aetosaurs () are heavily armored reptiles belonging to the extinct order Aetosauria (; from Greek, (aetos, "eagle") and (, "lizard")). They were medium- to large-sized omnivorous or herbivorous pseudosuchians, part of the branch of archosaurs m ...

will remain uncertain until more material can be found.

References

{{Taxonbar, from=Q860719 Aetosaurs Late Triassic pseudosuchians Late Triassic reptiles of South America Triassic Chile Fossils of Chile Antofagasta Region Fossil taxa described in 1980 Prehistoric pseudosuchian genera