Sarotrocercus

Sarotrocercus Temporal range: Burgess Shale PreꞒ Ꞓ O S D C P T J K Pg N ↓
Holotype
Reconstruction of Sarotrocercus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	incertae sedis
Genus:	†Sarotrocercus
Species:	†S. oblitus
Binomial name
†Sarotrocercus oblitus Whittington, 1981

Sarotrocercus is a small Cambrian arthropod known from Burgess shale, reaching a centimetre or two in length (0.39–0.79 in).[1] Sarotrocercus is only known from 7 specimens.[2] It may lie in the arthropod crown group, and a recent study has revised some points of its original description.[2]

Morphology

Sarotrocercus had a head shield followed by a trunk of 10 or 11 segments and a telson featuring a series of spines on the end.[2] A pair of big eyes at the end of stalks ventrally emerged from the front of the head.[2] The head bore two pairs of sturdy appendages that are armed with rows of inner spines.[2] At least the anterior 9 trunk segments each possess a pair of appendages, which are only known by lobe-like exopods that are fringed with setae.[2]

Ecology

In the original description, Sarotrocercus had been interpreted as a pelagic, nektonic animal that swam freely on its back, moving perhaps through movements of the trunk appendages and the action of its long tail tuft.[3] This was mainly based on the rarity of the specimens, as the Burgess Shale contains few swimming organisms; the submarine landslides that buried organisms mainly smothered benthic and nektobenthic organisms.[3][4] However, based on the redescription by Haug et al. 2011, Sarotrocercus may had been benthic or at least swimming close to the seafloor, as the robust head appendages rather suggest a grasping or raking function.[2]

External links

• "Sarotrocercus oblita". Burgess Shale Fossil Gallery. Virtual Museum of Canada. 2011. Archived from the original on 2020-11-12.

References

1. Briggs, D. E. G.; Erwin, D. H.; Collier, F. J. (1995), Fossils of the Burgess Shale, Washington: Smithsonian Inst Press, ISBN 1-56098-659-X, OCLC 231793738
2. Haug, J.T.; Maas, A.; Haug, C.; Waloszek, D. (2011). "Sarotrocercus oblitus - Small arthropod with great impact on the understanding of arthropod evolution?". Bulletin of Geosciences: 725–7??. doi:10.3140/bull.geosci.1283.
3. Whittington, H.B. (1981). "Rare Arthropods from the Burgess Shale, Middle Cambrian, British Columbia". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 292 (1060). The Royal Society: 329–357. Bibcode:1981RSPTB.292..329W. doi:10.1098/rstb.1981.0033. JSTOR 2395674.
4. Gabbott, S.E.; Zalasiewicz, J.; Collins, D. (2008). "Sedimentation of the Phyllopod Bed within the Cambrian Burgess Shale Formation of British Columbia". Journal of the Geological Society. 165 (1): 307–318. Bibcode:2008JGSoc.165..307G. doi:10.1144/0016-76492007-023. S2CID 128685811.