Sirius Passet
Sirius Passet | |
---|---|
Ma | |
Sirius sledge patrol | |
Named by | A. Higgins |
Location | J.P. Koch Fjord |
Year defined | 1987 |
Coordinates | 82°47.6′N 42°13.7′W / 82.7933°N 42.2283°W |
Country | Greenland |
Geologic Map with the Buen and the Portfjeld formations, and the Polkorridoren Group. |
Sirius Passet is a
Age
The fauna is inevitably compared to that of the
Preservation
The preservation of the Sirius Passet is traditionally considered to represent
Geochemical analysis indicates that the fossils lived close to the boundary of an oxygen minimum zone, possibly being preserved in oxygen-starved periods.[6]
IUGS geological heritage site
In respect of the importance of the exceptionally preserved fossils in our understanding of the event, the 'Cambrian Explosion in Sirius Passet' was included by the International Union of Geological Sciences (IUGS) in its assemblage of 100 'geological heritage sites' around the world in a listing published in October 2022. The organisation defines an 'IUGS Geological Heritage Site' as 'a key place with geological elements and/or processes of international scientific relevance, used as a reference, and/or with a substantial contribution to the development of geological sciences through history.'[7]
Fauna
Although the fauna has not yet been fully described, it is known to consist of a moderate number of arthropods and sponges, and rare representatives of other groups. It has yielded the problematic taxon , all of which have played prominent roles in discussions about the origins of the modern animal phyla.
Taxa from the Sirius Passet fauna
After[8]
Arthropods
Arthropods | |||
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Genus | Species | Notes | Images |
Aaveqaspis[9] | A. inesoni | An arthropod of uncertain affinitiies | |
Arthroaspis | A. bergstroemi | A member of Artiopoda | |
Buenaspis | B. forteyi | A nektaspid artiopod
|
|
Buenellus | B. higginsi | A trilobite | |
Campanamuta | C. mantoni | An artiopod | |
Kleptothule | K. rasmusseni | A trilobite | |
Molaria | M. steini | An artiopod | |
Sidneyia? | Indeterminate | A vicissicaudatan artiopod, later authors have stated that the assignment to the genus is equivocal.[10]
|
|
Thulaspis | T. tholops | A basal artiopodan closely related to Squamacula. | |
Siriocaris | S. trollae | A possible member of Lamellipedia | |
Isoxys | I. volucris, I. sp | A bivalved, freely swimming arthropod | |
Kiisortoqia | K. soperi | A basal arthropod with large frontal appendages | |
Kerygmachela | K. kierkegaardi | A "gilled lobopodian" closely related to arthropods | |
Pambdelurion | P. whittingtoni | A "gilled lobopodian" closely related to arthropods | |
Tamisiocaris | T. borealis | A filter feeding radiodont
|
|
Amplectobeluidae[11] | Indeterminate | Predatory radiodont | |
Pauloterminus | P. spinodorsalis | A shrimp-like arthropod, possibly a member of Hymenocarina |
Other animals
Non-arthropod animals | ||||
---|---|---|---|---|
Genus | Species | Notes | Images | |
Ooedigera[12] | O. peeli | A vetulicolian , another indeterminate vetulicolian is also present
|
||
Chordata[11]
|
Indeterminate | Vertebrate-like chordate | ||
Hadranax | H. augustus | A lobopodian
|
||
Halkieria
|
H. evangelista | A basal mollusc
|
||
Xystoscolex | X. boreogyrus | A palaeoscolecid worm | ||
Chalazoscolex | C. pharkus | A palaeoscolecid worm | ||
Timorebestia[11] | T. koprii | A giant stem-group chaetognath
|
||
Chaetognatha[11] | Indeterminate | Small-sized form | ||
Pygocirrus | P. butyricampum | An annelid worm | ||
Phragmochaeta[13]
|
P. canicularis | A polychaete worm | ||
Singuuriqia | S. simony | A priapulid worm
|
||
Sirilorica | S. carlsbergi, S. pustulosa | a stem-group scalidophoran
|
||
Hyolithus | H. cf. tenuis | A hyolith
|
||
Trapezovitus | Indeterminate | |||
Orthothecida | ||||
Hyolithida | ||||
Archaeocyatha | Indeterminate | A sponge | ||
Choia | C. cf. carteri | A sponge | ||
Constellatispongia | C. canismajorii | A sponge | ||
Crassicoactum | C. cucumis | A sponge | ||
Demospongiae
|
Indeterminate | A sponge | ||
Fieldospongia | F. bellineata | A sponge | ||
Hamptonia | H. limatula | A sponge | ||
Lenica | L. cf. unica L. hindei, L. perverse | A sponge | ||
Saetaspongia | S. cf. densa S. procera | A sponge | ||
Salactiniella | S. cf. plumata | A sponge | ||
Stephanella? | Indeterminate | A sponge |
See also
References
- .
- .
- .
- doi:10.1130/G38542.1.
- ISSN 0091-7613.
- PMID 30264482.
- ^ "The First 100 IUGS Geological Heritage Sites" (PDF). IUGS International Commission on Geoheritage. IUGS. Retrieved 10 November 2022.
- ISSN 0016-7649.
- ^ Peel, J.S.; Stein, M. "A new Arthropod from the Lower Cambrian Sirius Passet Fossil-Lagerstätten of North Greenland" (PDF). Bulletin of Geosciences. 84 (4): 1158.
- ISSN 0016-7568.
- ^ PMC 10796117.
- S2CID 85602402.
- .
Further reading
- Martin, M.W.; Grazhdankin, D.V.; Bowring, S.A.; Evans, D.A.D.; PMID 10797002.
- Harper, D. A. T.; Hammarlund, E. U.; Topper, T. P.; Nielsen, A. T.; Rasmussen, J. A.; Park, T.-Y. S.; Smith, M. P. (2019). "The Sirius Passet Lagerstätte of North Greenland: a remote window on the Cambrian Explosion". Journal of the Geological Society. 176 (6): 1023–1037. S2CID 198424068.