Fieldia (worm)

Fieldia
Temporal range: Middle Cambrian
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Stem group: Priapulida (?)
Class: †Archaeopriapulida
Family: †Fieldiidae
Genus: †Fieldia
Walcott, 1912
Species

Fieldia (named after American businessman and financier Cyrus W. Field) [1] is a genus of worms known from the Cambrian Burgess Shale, and assigned to the priapulids.[2]

It was originally interpreted as an arthropod; its trunk bears a dense covering of spines, and its proboscis is small.[2] It fed on sea-floor mud, evidenced by the frequent presence of sediments preserved in its gut.[2] It reached 5 cm in length.

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.[3] However, the morphological similarity of these organisms to their modern cousins is remarkable, especially for the Burgess Shale,[4] and their similarity to the modern genus Maccabeus suggests that they are in the Seticoronaria stem group, and thus are true crown-group priapulids.[3] A phylogenetic analysis does not provide a great deal of resolution to the relationships between these basal worms.[5]

18 species of Fieldia are known from the Greater Phyllopod bed, where they comprise 0.03% of the community.[6]

  1. ^ "Fieldia lanceolata". Burgess Shale Fossil Gallery. Virtual Museum of Canada. 2011.
  2. ^ a b c 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.
  3. ^ a b 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. S2CID 85091685.
  4. ^ 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. Bibcode:2004Letha..37...21H. doi:10.1080/00241160410005088.
  5. ^ Wills, M. A. (1 April 1998). "Cambrian and Recent Disparity: the Picture from Priapulids". Paleobiology. 24 (2): 177–199. doi:10.1666/0094-8373(1998)024[0177:CARDTP]2.3.CO;2. JSTOR 2401237. S2CID 88647544.
  6. ^ Caron, Jean-Bernard; Jackson, Donald A. (October 2006). "Taphonomy of the Greater Phyllopod Bed community, Burgess Shale". PALAIOS. 21 (5): 451–65. Bibcode:2006Palai..21..451C. doi:10.2110/palo.2003.P05-070R. JSTOR 20173022. S2CID 53646959.