1094 - Museum Grade Unique Spicomellus afer Oldest Ankylosaurian Dinosaur Dermal Spike - El Mers Fm

Scientific name: Spicomellus afer (Maidment et al., 2021) - Ankylosaurian Dinosaur - Dermal Spike

Location: Boulemane, Atlas Mountains, Morocco

Geological Formation: El Mers Fm = Guettioua Fm

Age: Middle Jurassic, Bathonian-Callovian, 167.7–164.7 Ma

Size: 11cm

Ref: 1094

Spicomellus (meaning "collar of spikes") is an extinct genus of herbivorous ankylosaurian dinosaur that lived in the supercontinent Gondwana during the Middle Jurassic Period. The genus name means "spiked collar", from the Latin 'spica' meaning spike, and 'mellum' meaning spiked dog collar and the specific name 'afer' means "the African".
Spicomellus is the second described eurypodan taxon from North Africa, after Adratiklit, and the oldest known ankylosaur from anywhere in the world.

Despite being a basal ankylosaurian, the preserved dermal spikes of the holotype were fused to the bone, which is a trait unique to Spicomellus and not known from any other vertebrate. Because the dermal spikes were fused to the bone instead of being attached to muscle tissue in all other ankylosaurs, this trait would probably have made it harder for the animal to move.

Though its exact size is unknown, it was likely comparable in size to other Middle Jurassic ankylosaurs like Sarcolestes and Tianchiasaurus. This puts our best size estimates for Spicomellus at no longer than 3 metres (9.8 ft) when fully grown.

Observations: The dermal spike has some glued and tiny filled restored fractures.