Protoconodont

Protoconodonts are an extinct taxonomic group of conodonts or, possibly, Chaetognaths.[2]

Protoconodont
Temporal range: Early Cambrian
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata? Chaetognatha?
Class:
†Conodonta?
Order:
†Protoconodonta

Genera

Chaetognaths (also known as arrow worms) were thought possibly to be related to some of the animals grouped with the conodonts. The conodonts themselves, however, are thought to be related to the vertebrates. It is now thought that protoconodont elements (e.g., Protohertzina anabarica Missarzhevsky, 1973), are probably grasping spines of chaetognaths rather than the oropharangeal elements of conodonts. Previously chaetognaths in the Early Cambrian were only suspected from these protoconodont elements (for example Phakelodus), but the more recent discoveries of body fossils have confirmed their presence then.[3]

References
  1. Upper Placentian-Branchian Series of Mainland Nova Scotia (Middle-Upper Lower Cambrian): Faunas, Paleoenvironments, and Stratigraphic Revision. Ed Landing, Journal of Paleontology, Vol. 69, No. 3 (May, 1995), pages 475-495 (Stable URL)
  2. Zooproblematica and mollusca from the Lower Cambrian Meishucun section (Yunnan, China) and taxonomy and systematics of the Cambrian small shelly fossils of China. P. Y. Parkhaev and Y. Demidenko, Paleontological Journal, 2010, volume 44, issue 8, pages 883-1161, doi:10.1134/s0031030110080010
  3. Szaniawski, H. (2002). "New evidence for the protoconodont origin of chaetognaths" (PDF). Acta Palaeontologica Polonica. 47 (3): 405–419.
  • Middle and Upper Cambrian Protoconodonts and Paraconodonts from Hunan, South China. Dong Xi-Ping and Stig M. Bergström, Palaeontology, September 2001, Volume 44, Issue 5, pages 949–985, doi:10.1111/1475-4983.00210
  • On the evolution and histology of some Cambrian protoconodonts, paraconodonts and primitive euconodonts. Dong Xiping, Science in China Series D: Earth Sciences, July 2004, Volume 47, Issue 7, pages 577–584, doi:10.1360/03yd0535
  • Ion microprobe U–Pb dating and Sr isotope measurement of a protoconodont. Yuji Sano, Kosaku Toyoshima, Akizumi Ishida, Kotaro Shirai, Naoto Takahata, Tomohiko Sato and Tsuyoshi Komiya, Journal of Asian Earth Sciences, Volume 92, 1 October 2014, Pages 10–17, doi:10.1016/j.jseaes.2014.05.024


This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.