| Aethocrinus Temporal range: | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Crinoidea |
| Family: | † Aethocrinidae |
| Genus: | † Aethocrinus |
Aethocrinus is an early-diverging crinoid reported from the Early Ordovician. [1] Its five arms bifurcate.
The contested Echmatocrinus notwithstanding, it is a candidate for the earliest true member of the crinoid class – though not being a member of the crown group, quite where within the stem group to draw the distinction between eocrinoids and crinoids is a somewhat arbitrary decision.
