Ptychagnostus

Ptychagnostus
Temporal range: Middle Cambrian
Ptychagnostus germanus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: †Trilobita (?)
Order: †Agnostida
Family: †Ptychagnostidae
Genus: †Ptychagnostus
Jaekel, 1909
Synonyms[1]
  • Triplagnostus Linnarsson, 1869
  • Huarpagnostus Rusconi, 1950
  • Solenagnostus Whitehouse, 1936
  • Pentagnostus Lermontova, 1940
  • Aristarius Opik, 1979
  • Aotagnostus Opik, 1979
  • Acidusus Opik, 1979
  • Canotagnostus Rusconi, 1951
  • Zeteagnostus Opik, 1979

Ptychagnostus is a member of the agnostida that lived during the Cambrian period. Ptychagnostidae generally do not exceed one centimetre in length.[1] Their remains are rarely found in empty tubes of the polychaete worm Selkirkia.[2] The genus probably ranged throughout the water column. It has two glabellar lobes, and three pygidial lobes.[3]

  1. ^ a b Samuel M. Gon III. "Agnostida Fact Sheet". A Guide to the Orders of Trilobites. Retrieved 18 November 2012.
  2. ^ Brian D. E. Chatterton, Desmond H. Collins & Rolf Ludvigsen (2003). "Cryptic behaviour in trilobites: Cambrian and Silurian examples from Canada, and other related occurrences". In Philip D. Lane, Derek J. Siveter & Richard A. Fortey (ed.). Trilobites and their Relatives: contributions from the third international conference, Oxford 2001. Special Papers in Palaeontology. Vol. 70. pp. 157–173. ISBN 978-0-901702-81-4.
  3. ^ Coppold, Murray and Wayne Powell (2006). A Geoscience Guide to the Burgess Shale, p.56. The Burgess Shale Geoscience Foundation, Field, British Columbia. ISBN 0-9780132-0-4.