Ptychagnostus
| Ptychagnostus Temporal range: Middle Cambrian | |
|---|---|
 | |
| Ptychagnostus germanus | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | †Trilobita |
| Order: | †Agnostida |
| Family: | †Ptychagnostidae |
| Genus: | †Ptychagnostus Jaekel, 1909 |
| Synonyms[1] | |
| |
Ptychagnostus is an extinct genus of blind trilobite that lived during the Cambrian period, part of the order Agnostida. Ptychagnostidae generally do not exceed ten millimetres in length.[1] Their remains are sometimes found in the otherwise empty tubes of the polychaete worm Selkirkia.[2] It probably lived in the water column. Its major characteristics are lack of eyes, two lobes on the glabella, and three lobes on the pygidium.[3]
Species
- Ptychagnostus aculeatus
- Ptychagnostus akanthodes
- Ptychagnostus atavus
- Ptychagnostus cassis
- Ptychagnostus ciceroides
- Ptychagnostus cuyanus
- Ptychagnostus fissus
- Ptychagnostus germanus
- Ptychagnostus gibbus
- Ptychagnostus hybridus
- Ptychagnostus intermedius
- Ptychagnostus michaeli
- Ptychagnostus praecurrens
- Ptychagnostus punctuosus
- Ptychagnostus seminula
References
- 1 2 Samuel M. Gon III. "Agnostida Fact Sheet". A Guide to the Orders of Trilobites. Retrieved 18 November 2012.
- ↑ 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. Trilobites and their Relatives: contributions from the third international conference, Oxford 2001. Special Papers in Palaeontology 70. pp. 157–173. ISBN 978-0-901702-81-4.
- ↑ 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.
External links
- "Ptychagnostus praecurrens". Burgess Shale Fossil Gallery. Virtual Museum of Canada. 2011.
Media related to Ptychagnostus at Wikimedia Commons
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