Temporal range: Middle Jurassic
Maidment et al., 2019
Maidment et al., 2019
Adratiklit is an extinct genus of herbivorous stegosaurian dinosaur that lived in the supercontinent Gondwana during the Middle Jurassic Period. The type and only known species is Adratiklit boulahfa. Its remains were found in the El Mers Group, probably in the El Mers II Formation (Bathonian), near Boulahfa, south of Boulemane, Fès-Meknes, Morocco.
Eurypodan dinosaurs, in particular stegosaurs, were during the Jurassic diverse and abundant in Laurasia (nowadays the northern continents), but their remains are extremely rare in deposits of Gondwana, nowadays the southern continents. Nevertheless, the existence of fragmentary remains and trackways in the deposits of Gondwana indicates the presence of eurypodan taxa there. Adratiklit is the first described eurypodan taxon from North Africa and the oldest known stegosaur from anywhere in the world, with the possible exception of Isaberrysaura.
Discovery and naming
Adratiklit boulahfa was described by Susannah C.R. Maidment, Thomas J. Raven and Paul M. Barrett on 16 August 2019 in an article published online in paleontological journal Gondwana Research. The holotype of Adratiklit boulahfa is a dorsal vertebra, NHMUK PV R37366. Referred specimens include three cervical vertebrae (NHMUK PV R37367 and NHMUK R37368, the latter specimen consisting of a series of two articulated bones), a dorsal vertebra (NHMUK PV R37365) and a left humerus (NHMUK PV R37007). The specimens were acquired, in the United Kingdom, from fossil traders by the Natural History Museum. They represent multiple individuals, probably five. While the second dorsal shares traits with the holotype, the other referrals are merely based on the fact that the material is stegosaurian. An attempt in 2018 to locate the site did not produce any relevant fossils but led to a deeper insight into the geology.
The generic name Adratiklit is derived from "adrar", a Berber word for "mountain", and "tiklit", a Berber word for lizard. The specific name, boulahfa, refers to Boulahfa near where the specimen was said to be found.
The humerus found has a length of sixty-one centimetres.
The describers established two autapomorphies, unique derived traits. With the dorsal vertebrae, the prezygapophysis has a small triangular rough protrusion on top, behind the front articulation facet of the vertebral body. With the dorsal vertebrae, the centroparapophysal laminae, the ridges between the vertebral body and the parapophyses, the contact facets for the lower rib heads, end in rough areas protruding to the front on both sides of the front opening of the neural canal. These traits are unique for the Stegosauria as a whole.
Adratiklit is a basal stegosaurian. It is more closely related to the European stegosaurs Dacentrurus and Miragaia than it is to the southern African taxa Kentrosaurus and Paranthodon. This places it in the subfamily Dacentrurinae, which was previously thought to be confined only to the Late Jurassic of Europe.