Wordie Creek Formation
The Wordie Creek Formation is an uppermost Permian and Lower Triassic geologic formation in Greenland, outcrops of which are located in Northeast Greenland National Park (until 2008 Tunu County, Danish: Østgrønland, English: East Greenland). In 2017, it was suggested to be raised to group status, as the Wordie Creek Group.[1]
| Wordie Creek Formation | |
|---|---|
| Stratigraphic range: late Changhsingian–early Dienerian | |
| Type | Formation |
| Unit of | Scoresby Land Group |
| Underlies | Pingo Dal Formation |
| Overlies | Schuchert Dal Formation |
| Lithology | |
| Primary | Mudstone |
| Other | Sandstone, conglomerate |
| Location | |
| Region | Clavering Ø, Hold with Hope (Kap Stosch), Gauss Halvø, Traill Ø, Jameson Land |
| Country |  Greenland |
  Wordie Creek Formation (Greenland) | |
The Lower Triassic sediments in the region were discovered in 1926 independently by James Wordie and Lauge Koch, and the latter named the formation.[1] The rock layers preserve fossils of invertebrates (e.g., ammonoids,[2] gastropods[1]), fishes (coelacanths, ray-finned fish, cartilaginous fish)[3][4] and temnospondyl amphibians,[5][6] dating back to the Induan age.[7]
Geology
Following Surlyk et al.[1], the Wordie Creek Group is subdivided into two formations, the Kap Stosch Formation and the overlying Godthåb Golf Formation. The Kap Stosch Formation was deposited in relatively deep, partly isolated turbiditic basin, and the Godthåb Golf Formation under relatively shallow marine conditions.
In 1935, Eigil Nielsen[8] recognized five fossil-bearing horizons ("fish zones 1–5")[9][10] corresponding to three ammonoid zones (in ascending order):
- Otoceras zone ("fish zones 1 and 2")
- Vishnuites zone ("fish zones 3 and 4")
- Proptychites zone ("fish zone 5")
The first two ammonoid zones are Griesbachian in age and the last one is Dienerian in age (Induan). The Kap Stosch Formation corresponds to these three zones. A sixth fossiliferous layer, the "Stegocephalian horizon", is present above, which belongs to the Godthåb Golf Formation (Dienerian). The Hypophiceras triviale ammonoid zone below Nielsen's "fish zones" is dated late Changhsingian.[1]
The Kap Stosch Formation is subdivided into the following eight members (in ascending order):[1]
- Nebalopok Member (upper Changhsingian–lower Griesbachian)
- Immaqa Member (lower Griesbachian)
- Fiskeplateau Member (lower Griesbachian)
- Knolden Member (lower Griesbachian)
- Pyramiden Member (lower–upper Griesbachian)
- Naasut Member (upper Griesbachian)
- Falkeryg Member (lower Dienerian)
- Vestplateau Member (lower Dienerian)
The Godthåb Golf Formation is not subdivided into members.[1]
Paleobiota
A diverse vertebrate fauna composed of temnospondyl amphibians and fishes is known from the formation.[3][5][11] Fossil fishes are also known from the Permian Ravnefjeld Formation ("Posidonomya shale") of Greenland.[8]
Amphibians
Color key
|
Notes Uncertain or tentative taxa are in small text; |
| Temnospondyls of the Wordie Creek Formation | ||||
|---|---|---|---|---|
| Taxon / Genus | Species | Subunit | Notes | Images |
| Luzocephalus[12] | L. johannsoni | ? | A lydekkerinid stereospondyl, originally described as "Lyrocephalus"[5] | |
| L. kochi | Kap Stosch Formation, Pyramiden Member ("Fish zone 2"), Falkeryg Member ("Fish zone 5")[1][8] | A lydekkerinid stereospondyl, originally described as "Lyrocephalus"[5] | ||
| L. rapax | Kap Stosch Formation, Falkeryg Member ("Fish zone 5")[1][8] | A lydekkerinid stereospondyl, originally described as "Lyrocephalus"[5] | ||
| Selenocara[13] | S. groenlandica | Godthåb Golf Formation ("Stegocephalian horizon")[1][8] | A mastodonsauroid, originally described as Wetlugasaurus groenlandicus[5] | |
| Stoschiosaurus | S. nielseni | Godthåb Golf Formation ("Stegocephalian horizon")[1][8] | A trematosaurid | |
| Tupilakosaurus | T. heilmani | Kap Stosch Formation, Falkeryg Member ("Fish zone 5")[1][8] | A tupilakosaurid dvinosaur[6][14] | |
Lobe-finned
Color key
|
Notes Uncertain or tentative taxa are in small text; |
| Sarcopterygii of the Wordie Creek Formation | ||||
|---|---|---|---|---|
| Taxon / Genus | Species | Subunit | Notes | Images |
| Laugia | L. groenlandica | Kap Stosch Formation, Pyramiden Member ("Fish zones 2–3")[8] | A laugiid coelacanth[3] | |
| Laugia sp. | Kap Stosch Formation ("Fish zone 1")[8] | A laugiid coelacanth[4] | ||
| Sassenia | S. groenlandica | ? | A rhabdodermatid coelacanth.[15] The genus is also known drom the Vikinghøgda Formation of Spitsbergen | |
| Whiteia | W. nielseni | ? | A whiteiid coelacanth.[4][15] The genus had a cosmopolitan distribution during the Triassic | |
| Coelacanthidae | Gen. et sp. indet. | ? | A complete head of a large coelacanthid.[4] | |
Ray-finned
Color key
|
Notes Uncertain or tentative taxa are in small text; |
| Actinopterygii of the Wordie Creek Formation | ||||
|---|---|---|---|---|
| Taxon / Genus | Species | Subunit | Notes | Images |
| Australosomus | A. kochi | Kap Stosch Formation, Pyramiden Member ("Fish zones 2–4") and Falkeryg Member ("Fish zone 5")[1][10] | A pholidopleuriform neopterygian. The genus had a cosmopolitan distribution during the Early Triassic epoch[3] | |
| A. simplex | Kap Stosch Formation (Pyramiden Member, "Fish zone 2")[1][10] | A pholidopleuriform neupterygian. The genus had a cosmopolitan distribution during the Early Triassic epoch[10] | ||
| A. aff. simplex | Kap Stosch Formation, Falkeryg Member ("Fish zone 5")[1][10] | A pholidopleuriform neupterygian. The genus had a cosmopolitan distribution during the Early Triassic epoch[10] | ||
| A. pholidopleuroides | Kap Stosch Formation (Pyramiden Member, "Fish zone 2")[1][10] | A pholidopleuriform neupterygian. The genus had a cosmopolitan distribution during the Early Triassic epoch[10] | ||
| Birgeria | B. groenlandica | Kap Stosch Formation, Pyramiden Member ("Fish zone 2"), Falkeryg Member ("Fish zone 5")[1][10] | A birgeriid. The genus had a cosmopolitan distribution during the Triassic[3][10] | |
| Bobasatrania | B. groenlandica | Kap Stosch Formation, Pyramiden Member ("Fish zones 2–3")[1][8] | A bobasatraniform[3][16] The genus had a cosmopolitan distribution during the Triassic | |
| Bobasatrania sp. | Nebalopok Member[1] | A bobasatraniform. One of the few Permian occurrences of the genus[7] | ||
| Boreosomus | B. piveteaui | Kap Stosch Formation, Pyramiden Member ("Fish zones 2–4"), Falkeryg Member ("Fish zone 5")[1][9] | A ptycholepid. The genus had a cosmopolitan distribution during the Early Triassic epoch[9] | |
| Broughia | B. perleididoides | Kap Stosch Formation, Pyramiden Member ("Fish zone 3"), Falkeryg Member ("Fish zone 5")[1][8] | A parasemionotiform neopterygian[3] | |
| Helmolepis | H. gracilis | Kap Stosch Formation, Pyramiden Member ("Fish zones 2–4")[1] | A platysiagid neopterygian. The genus had a cosmopolitan distribution during the Early Triassic[3][17] | |
| Ospia | O. whitei | Kap Stosch Formation, Pyramiden Member ("Fish zone 3"), Falkeryg Member ("Fish zone 5")[1][8] | A parasemionotiform neopterygian[3] | |
| Pteronisculus | P. arcticus | Kap Stosch Formation, Pyramiden Member ("Fish zone 2")[9] | A rhadinichthyid or turseoid, It was originally described as Glaucolepis arctica,[3] but later referred to the genus Pteronisculus because the genus name Glaucolepis is preoccupied | |
| P. aldingeri | Kap Stosch Formation, Pyramiden Member ("Fish zones 2 and 4")[9] | A rhadinichthyid or turseoid, It was originally described as Glaucolepis aldingeri,[9] but later referred to the genus Pteronisculus because the genus name Glaucolepis is preoccupied | ||
| P. gunnari | Kap Stosch Formation, Pyramiden Member ("Fish zones 2?–3")[9] | A rhadinichthyid or turseoid, It was originally described as Glaucolepis gunnari,[9] but later referred to the genus Pteronisculus because the genus name Glaucolepis is preoccupied | ||
| P. magnus | Kap Stosch Formation, Falkeryg Member ("Fish zone 5")[9] | A rhadinichthyid or turseoid, It was originally described as Glaucolepis magna,[9] but later referred to the genus Pteronisculus because the genus name Glaucolepis is preoccupied | ||
| P. stensioei | Kap Stosch Formation, Falkeryg Member ("Fish zone 5")[9] | A rhadinichthyid or turseoid, It was originally described as Glaucolepis stensioei,[9] but later referred to the genus Pteronisculus because the genus name Glaucolepis is preoccupied | ||
| Pteronisculus sp. | Kap Stosch Formation, Pyramiden Member ("Fish zones 2–4"), Godthåb Golf Formation ("Stegocephalian horizon")[9] | A rhadinichthyid or turseoid, It was originally referred to the genus Glaucolepis,[9] a homonym of Pteronisculus | ||
| Saurichthys | S. aff. dayi | Kap Stosch Formation, Pyramiden Member ("Fish zone 2"), Falkeryg Member ("Fish zone 5")[18] | A saurichthyiform with a dense squamation[4][18] | |
| S. cf. ornatus[19] | Kap Stosch Formation, Falkeryg Member ("Fish zone 5")[19] | A three-dimensionally preserved skull of a saurichthyiform, which was analyzed using μCT-aided tomography[20] | ||
| Teffichthys | T. stoschiensis | Kap Stosch Formation, Pyramiden Member ("Fish zones 2–4"), Falkeryg Member ("Fish zone 5")[8] | A perleidiform neopterygian. It was originally described as Perleidus stoschiensis,[3]. Early Triassic species of Perleidus were subsequently referred to the genus Teffichthys[21] | |
Cartilaginous
Color key
|
Notes Uncertain or tentative taxa are in small text; |
| Chondrichthyes of the Wordie Creek Formation | ||||
|---|---|---|---|---|
| Taxon / Genus | Species | Subunit | Notes | Images |
| Polyacrodus | P. claveringensis | Kap Stosch Formation, Pyramiden Member ("Fish zone 2")[8][4] | A polyacrodontid hybodontiform shark. Known from isolated teeth[3] and partial skeletons with fin spines[4] | |
| Nemacanthus? | N.? sp. | "Fish zone 1"[8] | Fin spines of the Nemacanthus-type[3] | |
| Edestidae | Gen. et sp. indet | Kap Stosch Formation, Pyramiden Member ("Fish zone 2")[8] | Symphyseal tooth whorl of a eugeneodontid holocephalian[8][4] | |
| Hybodontiformes | Gen. et sp. indet | "Fish zone 1"[8] | Fin spines of the Hybodus/Acrodus-type[3] | |
References
- Surlyk, Finn; Bjerager, Morten; Piasecki, Stefan; Stemmerik, Lars (2017). "Stratigraphy of the marine Lower Triassic succession at Kap Stosch, Hold with Hope, North-East Greenland". Bulletin of the Geological Society of Denmark. 65: 87–123. doi:10.37570/bgsd-2017-65-07. ISSN 2245-7070.
- Spath, Leonard F. (1935). "Additions to the Eo-Triassic invertebrate fauna of East Greenland". Meddelelser om Grønland. 98 (2): 1–11.
- Stensiö, Erik (1932). "Triassic Fishes from East Greenland collected by the Danish expeditions in 1929-1931". Meddelelser om Grønland. 83 (3): 1–305. OCLC 938169014.
- Nielsen, Eigil (1936). "Some few preliminary remarks on Triassic fishes from East Greenland". Meddelelser om Grønland. 112 (3): 1–55.
- Säve-Söderbergh, Gunnar (1935). "On the dermal bones of the head in labyrinthodont stegocephalians and primitive Reptilia with special reference to Eotriassic stegocephalians from East Greenland". Meddelelser om Grønland. 98 (3): 1–211..
- Nielsen, Eigil (1954). "Tupilakosaurus heilmani n. g. et n. sp. an interesting batrachomorph from the Triassic of East Greenland". Meddelelser om Grønland. 722 (8): 1–33.
- Stemmerik, Lars; Bendix-Almgreen, Svend E.; Piasecki, Stefan (2001). "The Permian-Triassic boundary in central East Greenland: past and present views". Bulletin of the Geological Society of Denmark. 48: 159–167. doi:10.37570/bgsd-2001-48-09.
- Nielsen, Eigil (1935). "The Permian and Eotriassic vertebrate-bearing beds at Godthaab Gulf (East Greenland)". Meddelelser om Grønland. 98 (1): 1–111.
- Nielsen, Eigil (1942). "Studies on Triassic fishes from East Greenland 1. Glaucolepis and Boreosomus". Palaeozoologica Groenlandica. 1: 1–403.
- Nielsen, Eigil (1949). "Studies on Triassic fishes from East Greenland 2. Australosomus and Birgeria". Palaeozoologica Groenlandica. 3: 1–309.
- Brinkmann, Winand; Romano, Carlo; Bucher, Hugo; Ware, David; Jenks, Jim (2010). "Palaeobiogeography and stratigraphy of advanced gnathostomian fishes (Chondrichthyes and Osteichthyes) in the Early Triassic and from selected Anisian localities (Report 1863–2009)" (PDF). Zentralblatt für Geologie und Paläontologie, Teil 2. 2009: 765–812..
- Warren, Anne (1998). "Laidleria uncovered: a redescription of Laidleria gracilis Kitching (1957), a temnospondyl from the Cynognathus Zone of South Africa". Zoological Journal of the Linnean Society. 122 (1–2): 167–185. doi:10.1111/j.1096-3642.1998.tb02528.x.
- Bjerring, Hans C. (1997). "The question of the Eotriassic tetrapod genus Wetlugasaurus in Greenland and thoughts on the fossa coniformis entopterygoidea". Meddelelser om Grønland, Geoscience. 34: 1–25. ISBN 9788763512497.
- Nielsen, Eigil (1967). "New observations on the skull-roof of the holotype of Tupilakosaurus heilmani Nielsen". Journal of the Linnean Society (Zoology). 47 (311): 225–229. doi:10.1111/j.1096-3642.1967.tb01405.x.
- Forey, Peter L. (1998). History of the coelacanth fishes. London: Chapman & Hall. p. 434. ISBN 9780412784804..
- Nielsen, Eigil (1952). "A preliminary note on Bobasatrania groenlandica" (PDF). Meddelelser Fra Dansk Geologisk Forening. 12 (12): 197–204.
- Nybelin, Orvar (1977). "Studies on Triassic fishes from East Greenland III. On Helmolepis gracilis Stensiö". Meddelelser om Grønland. 200: 1–13.
- Kogan, Ilja (2011). "Remains of Saurichthys (Pisces, Actinopterygii) from the Early Triassic Wordie Creek Formation of East Greenland". Bulletin of the Geological Society of Denmark. 59: 93–100. ISSN 0011-6297.
- Mutter, Raoul J.; Cartanyà, Joan; Basaraba, Susan A. U. (2008). "New evidence of Saurichthys from the Lower Triassic with an evaluation of early saurichthyid diversity". In G. Arratia; H.-P. Schultze; M. V. H. Wilson (eds.). Mesozoic fishes 4. Homology and phylogeny. München: Dr. Friedrich Pfeil. pp. 103–127.
- Argyriou, Thodoris; Giles, Sam; Friedman, Matt; Romano, Carlo; Kogan, Ilja; Sánchez-Villagra, Marcelo R. (2018). "Internal cranial anatomy of Early Triassic species of †Saurichthys (Actinopterygii: †Saurichthyiformes): implications for the phylogenetic placement of †saurichthyiforms". BMC Evolutionary Biology. 18 (1): 161. doi:10.1186/s12862-018-1264-4. ISSN 1471-2148. PMC 6211452. PMID 30382811.
- Marramà, G.; Lombardo, C.; Tintori, A. & Carnevale, G. (2017). "Redescription of "Perleidus"(Osteichthyes, Actinopterygii) from the Early Triassic of northwestern Madagascar". Rivista Italiana di Paleontologia e Stratigrafia. 123 (2): 219–242. doi:10.13130/2039-4942/8328.
- Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.
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