Fieldia (animal)

Fieldia
Temporal range: Middle Cambrian
Scientific classification
Kingdom: Animalia
Stem-group: Priapulida
Class: Archaeopriapulida
Family: Fieldiidae
Genus: Fieldia
Walcott, 1912
Species
  • F. lanceolata Walcott, 1912

Fieldia is a genus of worm known from the Cambrian Burgess Shale, and assigned to the Priapulids.[1] It was originally interpreted as an arthropod; its trunk bears a dense covering of spines, and its proboscis is small.[1] It fed on sea-floor mud, evidenced by the frequent presence of sediments preserved in its gut.[1]

Along with the other Cambrian priapulids Ottoia, Selkirkia, Louisella, Ancalagon, Scolecofurca, and Lecythioscopa, the organism was originally classified into a clade termed the archaeopriapulida, a stem group to the Priapulids proper.[2] However, the morphological similarity of these organisms to their modern cousins is remarkable, especially for the Burgess Shale,[3] and their similarity to the modern genus Maccabeus suggests that they are in the Seticoronaria stem group, and thus are true crown-group priapulids.[2] A phylogenetic analysis does not provide a great deal of resolution to the relationships between these basal worms.[4]

18 specimens of Fieldia (animal) are known from the Greater Phyllopod bed, where they comprise 0.03% of the community.[5]

External links

References

  1. 1.0 1.1 1.2 Conway Morris, S. (1979). "The Burgess Shale (Middle Cambrian) Fauna". Annual Review of Ecology and Systematics 10: 327–349. doi:10.1146/annurev.es.10.110179.001551.
  2. 2.0 2.1 Por, F. D. (1983). "Class Seticoronaria and Phylogeny of the Phylum Priapulida". Zoologica Scripta 12 (4): 267–272. doi:10.1111/j.1463-6409.1983.tb00510.x.
  3. Huang, D. Y.; Vannier, J.; Chen, J.Y. (2004). "Anatomy and lifestyles of Early Cambrian priapulid worms exemplified by Corynetis and Anningvermis from the Maotianshan Shale (SW China)". Lethaia 37: 21–33. doi:10.1080/00241160410005088.
  4. Wills, M. A. (1 April 1998). "Cambrian and Recent Disparity: the Picture from Priapulids". Paleobiology 24 (2): 155–286. doi:10.2307/2401237 (inactive 2015-03-21). JSTOR 2401237.
  5. Caron, Jean-Bernard; Jackson, Donald A. (October 2006). "Taphonomy of the Greater Phyllopod Bed community, Burgess Shale". PALAIOS 21 (5): 451–65. doi:10.2110/palo.2003.P05-070R. JSTOR 20173022.