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Opabiniidae

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Opabiniidae
Temporal range: Middle Cambrian - Middle Ordovician, 507–475 Ma
Opabinia (top) and Utaurora (bottom)
Scientific classification Edit this classification
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

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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

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  1. ^ Tamisiea, Jack (8 February 2022). "One of Evolution's Oddest Creatures Finds a Fossilized Family Member - Opabinia, which swam the seas of Earth's Cambrian era some 500 million years ago, was not just a one hit wonder". The New York Times. Retrieved 10 February 2022.
  2. ^ a b c Pates et al. 2022.
  3. ^ Walcott 1912.
  4. ^ Whittington 1975.
  5. ^ Briggs, D. E. G.; Nedin, C. (1997). "The Taphonomy and Affinities of the Problematic Fossil Myoscolex from the Lower Cambrian Emu Bay Shale of South Australia". Journal of Paleontology. 71 (1): 22–32. doi:10.1017/S0022336000038919. JSTOR 1306537. S2CID 131851540.
  6. ^ Dzik, Jerzy (2004). "Anatomy and relationships of the Early Cambrian worm Myoscolex". Zoologica Scripta. 33 (1): 57–69. doi:10.1111/j.1463-6409.2004.00136.x. ISSN 1463-6409. S2CID 85216629.

Works cited

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