Cambrorhytium

Cambrorhytium Temporal range: Chengjiang - Burgess Shale
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Cnidaria
Order:	†Conulatae
Clade:	†Conulariida
Genus:	†Cambrorhytium (Walcott 1908) Conway Morris and Robison, 1988[1]
Species
C. elongatum C. fragilis Walcott 1911 C. gracilis Chang et al. 2018 C. major Walcott 1908 (type)

Cambrorhytium is an enigmatic fossil genus known from the Latham Shale (California),[2] and the Chengjiang (China) and Burgess Shale (Canadian rockies) lagerstätte.[3] 350 specimens of Cambrorhytium are known from the Greater Phyllopod bed, where they comprise 0.7% of the community.[4]

Etymology

Its name is from the Latin rhytium, drinking horn.[1]

Description

The fossil is conical, with iterated linear markings on its walls, parallel to its base. Its wall is thin, and it lacks the keel that is distinctive of hyoliths.[2]

It has been interpreted as a cnidarian polyp, with the interpretation suggesting that the animal lived in the tube and extended tentacles (of which no trace has been found) from the flat aperture.[5] This is supported by similarities to Palaeoconotuba.[6] The other possible, but probably unlikely, affinity is with the hyoliths.[2]

Its similarity with the Lower Cambrian species Torellelloides giganteum may indicate a close relationship.[1] Cambrorhytium has also been compared to the fossil Archotuba[5] and Sphenothallus.[7]

C. elongatum has been described to contain an alimentary canal in a single Chinese specimen.[8]

Taxonomy

C. major was originally described as a member of the hyolith genus Orthotheca.[9]

C. fragilis was originally included by Charles D. Walcott in the genus Selkirkia,[10][11] – a taxonomy that was retained by later workers[12][13] until finally questioned[14] and redescribed[1] as Cambrorhytium in the eighties.

References

1. Conway Morris, Simon; Robison, R.A. (1988). "More soft-bodied animals and algae from the Middle Cambrian of Utah and British Columbia" (PDF). University of Kansas Paleontological Contributions. 122: 1–48.
2. Waggoner, Ben; Hagadorn, James W. (2005). "Conical fossils from the Lower Cambrian of Eastern California". PaleoBios. 25 (1).
3. Zhang, X. L.; Hua, H. (2005). "Soft-bodied fossils from the Shipai Formation, Lower Cambrian of the Three Gorge area, South China". Geological Magazine. 142 (6): 699. Bibcode:2005GeoM..142..699Z. doi:10.1017/S0016756805000518. S2CID 129323140.
4. 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.
5. Han, J.; Zhang, Z.; Liu, J.; Shu, D. (2007). "Evidence of Priapulid Scavenging from the Early Cambrian Chengjiang Deposits, Southern China". PALAIOS. 22 (6). Society for Sedimentary Geology: 691–694. Bibcode:2007Palai..22..691H. doi:10.2110/palo.2006.p06-117r. ISSN 0883-1351. S2CID 86584623.^[permanent dead link‍]
6. Qu, Hanzhi; Li, Kexin; Ou, Qiang (2023). "Thecate stem medusozoans (Cnidaria) from the early Cambrian Chengjiang biota". Palaeontology. 66 (1): 12636. Bibcode:2023Palgy..6612636Q. doi:10.1111/pala.12636. S2CID 256562444.
7. Van Iten, H.; Zhu, M. Y.; Collins, D. (2002). "First Report of Sphenothallus Hall, 1847 in the Middle Cambrian". Journal of Paleontology. 76 (5): 902–905. doi:10.1666/0022-3360(2002)076<0902:FROSHI>2.0.CO;2. ISSN 0022-3360. JSTOR 1307202. S2CID 131018299.
8. Steiner, M.; Zhu, M.; Zhao, Y.; Erdtmann, B. (2005). "Lower Cambrian Burgess Shale-type fossil associations of South China". Palaeogeography, Palaeoclimatology, Palaeoecology. 220 (1–2): 129–152. Bibcode:2005PPP...220..129S. doi:10.1016/j.palaeo.2003.06.001.
9. Walcott, C. D. (1908). "Mount Stephen rocks and fossils". Canadian Alpine Journal. 1: 232–248.
10. Walcott, C.D. (1911). "Cambrian Geology and Paleontology II, no. 5. Middle Cambrian annelids". Smithsonian Miscellaneous Collections. 57: 109–144.
11. Walcott, C.D. (1912). "Cambrian of the Kicking Horse Valley, B.C.". Geological Survey of Canada Report. 26: 188.
12. Howell, B. F.; Stubblefield, C. J. (2009). "A Revision of the Fauna of the North Welsh Conocoryphe viola Beds implying a Lower Cambrian Age". Geological Magazine. 87: 1–16. doi:10.1017/S0016756800075506. S2CID 129709736.
13. Conway Morris, S (1977). "Fossil priapulid worms". Special Papers in Palaeontology. 20: 1–95.
14. Briggs, D.E.G.; S. Conway Morris (1986). "Problematica from the Middle Cambrian Burgess Shale of British Columbia.". In Hoffman, A., M.H.; Nitecki (eds.). Problematic Fossil Taxa. New York: Oxford University Press.

External links

• "Cambrorhytium major". Burgess Shale Fossil Gallery. Virtual Museum of Canada. 2011. Archived from the original on 2023-09-25. Retrieved 2023-10-23.