Stegouros

Stegouros Temporal range: Late Cretaceous PreЄ Є O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Order:	†Ornithischia
Suborder:	†Thyreophora
Infraorder:	†Ankylosauria
Genus:	†Stegouros Soto-Acuña, 2021
Species:	†S. elengassen
Type species
†Stegouros elengassen Soto-Acuña, 2021

Stegouros elengassen is an extinct genus of ankylosaur from the Late Cretaceous of Magallanes in southern most Chile, a region biogeographically related to West Antarctica.

Description

Stegouros was about 2 meters long, a relatively small herbivore. It evolved a large tail weapon unlike any dinosaur: A flat, frond-like structure formed by pairs of laterally projecting osteoderms encasing the distal half of the tail. Stegouros shows ankylosaurian cranial characters, but a largely primitive postcranial skeleton, with some stegosaur-like characters.

Phylogenetic analyses places Stegouros in Ankylosauria, and specifically related to Kunbarrasaurus from Australia and Antarctopelta from Antarctica, forming a clade of Gondwanan ankylosaurs that split earliest from all other ankylosaurs. Large osteoderms and specialized tail vertebrae in Antarctopelta suggest it had a tail weapon similar to Stegouros. A new clade, called the Parankylosauria, has been proposed to include the first ancestor of Stegouros but not Ankylosaurus, and all descendants of that ancestor.

Gallery

Illustration of Stegouros elengassen.png

Art reconstruction of Stegouros elengassen.png

Sketch reconstruction of Stegouros elengassen.png

Holotype fossils of Stegouros

Stegouros fighting Imperobator in Amazing Dinoworld 2.