Opabiniidae

Opabiniidae
Opabinia (top) and Utaurora (bottom)
Scientific classification
Kingdom: Animalia
Stem group: Arthropoda
Class: Dinocaridida
Order: Opabiniida
Family: Opabiniidae
Walcott, 1912
Genera

Opabiniidae is an extinct family of marine stem-arthropods. Its type and best-known genus is Opabinia. It also contains Utaurora, and Mieridduryn. Opabiniids closely resemble radiodonts, but their frontal appendages were basally fused into a proboscis. Opabiniids are also distinguishable from radiodonts by setal blades covering at least part of the body flaps and serrated caudal rami.