Spicomellus Afer

The Ankylosaur With a Spiked Collar

The armour‑plated ankylosaurs are often pictured as tank‑like dinosaurs covered in bony plates and wielding heavy tail clubs. Spicomellus afer from Morocco, however, took defence to a new extreme: its skeleton shows metre‑long spikes fused directly to the ribs, forming a collar of spines around its neck and shoulders. Described in 2024, this ankylosaur dates to the Middle Jurassic—around 168 million years ago—and predates the more familiar club‑tailed ankylosaurs by tens of millions of years.

The fossil is fragmentary, consisting of ribs with spines attached, but the anatomy is unlike anything seen in other dinosaurs. Each rib bears a long, bony spine that protruded outward, creating a formidable barrier to predators. Some ribs also show evidence of a tail weapon, hinting that Spicomellus may have sported both neck spikes and a rudimentary tail club. Palaeontologists speculate that the spines served both defensive and display functions. In modern animals, such extravagant armaments often signal strength to rivals and potential mates as much as they deter predators.

Spicomellus pushes back the origin of ankylosaur armour by about 30 million years. It suggests that the earliest members of the group were experimenting with different ways of protecting themselves. Later ankylosaurs replaced spined collars with armour plates and evolved heavy tail clubs. This evolutionary tinkering mirrors what is seen in other dinosaur lineages, where early species display a surprising variety of forms before settling into more standard patterns. For palaeontologists, Spicomellus is both a curiosity and an important piece in the puzzle of how armoured dinosaurs evolved.

Credit: Clumsystiggy / CC BY‑SA 4.0

Sources: ScienceDaily article on Spicomellus afer.