Cassiduloida
| Cassiduloida Temporal range: | |
|---|---|
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Class: | |
| Superorder: | |
| Order: | Cassiduloida L. Agassiz & Desor, 1847 |
| Families | |
Cassiduloida is an order of sea urchins. The group was extremely diverse with many families and species during the Mesozoic, but today, only seven extant species remain.
A 2019 phylogenetic systematics study by Souto et al. presented a revised classification of the cassiduloids, and hypothesised that the order probably originated in the Early Cretaceous.