Biology:Opabiniidae

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Short description: Extinct family of basal arthropods

Opabiniidae
Temporal range: Middle Cambrian - Middle Ordovician, 507–475 Ma
20220213 Opabiniidae Opabiniids.png
Opabinia (top) and Utaurora (bottom)
Scientific classification e
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Dinocaridida
Family: Opabiniidae
Walcott, 1912
Genera

Opabiniidae is an extinct family of marine stem-arthropods.[1] 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 also distinguishable from radiodonts by setal blades covering at least part of the body flaps and serrated caudal rami.[2]

Cross section
Size comparison

History of study

Opabiniidae was named by Charles Doolittle Walcott in 1912, alongside its type species Opabinia. Walcott interpreted Opabiniidae as a family of anostracan crustaceans, most closely related to Thamnocephalidae.[3] Opabinia was restudied in the 1970s, and reinterpreted as a stranger animal. Stephen Jay Gould referred to Opabinia as a "weird wonder", and an illustration of Opabinia prompted laughter when it was first revealed at a paleontological conference.[4] In 2022, more Opabiniids were discorvered. That being Utaurora, and Mieridduryn.[2]

Myoscolex from Emu Bay Shale is sometimes suggested to be an opabiniid,[5] but morphological features supporting this interpretation are controversial.[6][2]

References

Works cited

Wikidata ☰ Q110903763 entry