Spicomellus

Spicomellus
Temporal range:
Middle Jurassic,
Skeletal reconstruction including the holotype (yellow) and referred (white) specimens
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Dinosauria
Clade: Ornithischia
Clade: Thyreophora
Clade: Ankylosauria
Genus: Spicomellus
Maidment et al., 2021
Species:
S. afer
Binomial name
Spicomellus afer
Maidment et al., 2021

Spicomellus is an extinct genus of unusual early ankylosaurian dinosaur from the El Mers III Formation (Bathonian age) of Morocco. The genus contains a single species, Spicomellus afer, representing the oldest named definitive ankylosaur. The species was initially described in 2021 based on a single rib with fused osteoderms, rendering its life appearance and relationships uncertain. In 2025, several additional bones, including osteoderms and cranial and postcranial remains, were described, revealing that it bears a unique array of spines over the body, including extremely elongated spikes around the neck and pelvis. It likely had a tail weapon, making it the oldest known ankylosaur with this structure.