I attended the 2019 Tucson show and a Moroccan dealer had a strange partial spike for sale. Purchased it and thought it might be ankylosaurian. Well a paper was just published that identifies it as the oldest Ankylosaur known, Spicomellus afer. From the El Mers III formation where the oldest Stegosaurus was found. It differs from all other known armoured dinosaurs that these spikes are fused on the dorsal ribs, pretty cool critter.
Paper (paywalled but it opened up for me)
https://www.nature.com/articles/s41559-021-01553-6
Articles
https://www.nhm.ac.uk/press-office/bizarre-armoured-spikes-belong-to-oldest-ankylosaur-ever-discove.ht
https://www.bbc.com/news/science-environment-58657862
https://news.sky.com/story/life-finds-a-way-unusual-fossil-found-in-morocco-is-new-species-of-dinosaur-12415509
Photo from @Dinocollector who asked about this one last year