Mosasaur Teeth from Morocco: Sea Lizards at the End of the Cretaceous

Mosasaur tooth in phosphate matrix from Morocco

By Adam Kelliher

Mosasaur teeth are one of those fossils that sell themselves. They're sharp, they're shiny, and they came out of the mouth of a sea lizard the size of a bus. Almost all of ours come from the phosphate mines of Morocco, and there's a good reason for that.

Why Morocco

The Late Cretaceous phosphates of Morocco are, in the words of a 2025 study, the richest outcrop in the world for mosasaurs, with at least fifteen species living at the same time.[1] The phosphates were laid down in a shallow arm of the Atlantic that flooded North Africa, and the upper beds formed about a million years or less before the extinction that ended the Cretaceous.[2] The Oulad Abdoun and Ganntour basins are mined for phosphate, and that mining is what brings the fossils up.[1]

Mosasaur tooth in phosphate matrix from Morocco
Mosasaur tooth still sitting in its phosphate matrix, Morocco. (photo: Rubble Rock & Gem)

Teeth for different jobs

Mosasaur teeth come in a surprising range of shapes. Researchers group them by function, piercing, cutting or crushing, and use that to work out who ate what and how the species split up the menu.[1] One giant, Thalassotitan atrox, had robust conical teeth that the authors compared to a killer whale's, often heavily worn and broken.[2]

What you're actually holding

A shed mosasaur tooth is the crown, sometimes with part of the root. Shed teeth are common because, like sharks, mosasaurs replaced teeth through life. Our small Oulad Abdoun mosasaur teeth are a good first fossil, and the teeth on matrix show what the phosphate rock looks like. Be aware that matrix pieces are sometimes assembled, so ask if that matters to you.

Mosasaurs were reptiles, not dinosaurs. They died out with the dinosaurs at the end of the Cretaceous, but they swam a very different road.

See what's new: browse our newest arrivals for the latest pieces added to the shop.

Sources

  1. 2025. Mosasaurids bare the teeth: an extraordinary ecological disparity in the Phosphates of Morocco just prior to the K/Pg crisis. Diversity 17(2):114.
  2. Longrich, N.R. et al. 2022. Thalassotitan atrox, a giant predatory mosasaurid from the upper Maastrichtian phosphates of Morocco. Cretaceous Research.

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