Wordie Creek Formation
{{short description|Geologic formation in Greenland}}
{{Infobox rockunit
| name = Wordie Creek Formation
| image =Akuliarusiarsuup-kuua-sugarloaf-ravine-greenland.jpg
| caption =The “Roapaluk Fjord” track site at the Wordie Creek Formation
| type = Formation
| age = late Changhsingian–early Dienerian
| period = Induan
| prilithology = Mudstone
| otherlithology = Sandstone, conglomerate
| namedfor =
| namedby =
| region = Clavering Ø, Hold with Hope (Kap Stosch), Gauss Halvø, Traill Ø, Jameson Land
| country = Greenland
| coordinates =
| unitof = Scoresby Land Group
| subunits =
| underlies = Pingo Dal Formation
| overlies = Schuchert Dal Formation
| thickness =
| extent =
| area =
| map = {{Location map+ | Greenland
| relief = 1
| width = 250
| float = center
| places = {{Location map~ | Greenland
| lat_deg = 74.16
| lon_deg = -21.00
| mark = Pink ff0080 pog.svg
| marksize = 10
}}
}}
| map_caption =
}}
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.{{cite journal |last1=Surlyk |first1=Finn |last2=Bjerager |first2=Morten |last3=Piasecki |first3=Stefan |last4=Stemmerik |first4=Lars |year=2017 |title=Stratigraphy of the marine Lower Triassic succession at Kap Stosch, Hold with Hope, North-East Greenland |journal=Bulletin of the Geological Society of Denmark |volume=65 |pages=87–123 |issn=2245-7070 |doi=10.37570/bgsd-2017-65-07|doi-access=free }}
The Lower Triassic sediments in the region were discovered in 1926 independently by James Wordie and Lauge Koch, and the latter named the formation. The rock layers preserve fossils of invertebrates (e.g., ammonoids,{{cite journal |last=Spath |first=Leonard F. |author-link=Leonard Frank Spath |year=1935 |title=Additions to the Eo-Triassic invertebrate fauna of East Greenland |journal=Meddelelser om Grønland |volume=98 |issue=2 |pages=1–11}} gastropods), fishes (coelacanths, ray-finned fish, cartilaginous fish){{cite journal |first=Erik |last=Stensiö |author-link=Erik Stensiö |year=1932 |title=Triassic Fishes from East Greenland collected by the Danish expeditions in 1929-1931 |journal=Meddelelser om Grønland |volume=83 |issue=3 |pages=1–305 |oclc=938169014 |url=https://www.worldcat.org/oclc/938169014}}{{cite journal |last=Nielsen |first=Eigil |author-link=Eigil Nielsen (paleontologist) |year=1936 |title=Some few preliminary remarks on Triassic fishes from East Greenland |journal=Meddelelser om Grønland |volume=112 |issue=3 |pages=1–55}} and temnospondyl amphibians,{{cite journal |last=Säve-Söderbergh |first=Gunnar |author-link=Gunnar Säve-Söderbergh |year=1935 |title=On the dermal bones of the head in labyrinthodont stegocephalians and primitive Reptilia with special reference to Eotriassic stegocephalians from East Greenland |journal=Meddelelser om Grønland |volume=98 |issue=3 |pages=1–211}}.{{cite journal |last=Nielsen |first=Eigil |author-link=Eigil Nielsen (paleontologist) |year=1954 |title=Tupilakosaurus heilmani n. g. et n. sp. an interesting batrachomorph from the Triassic of East Greenland |journal=Meddelelser om Grønland |volume=722 |issue=8 |pages=1–33}} dating back to the Induan age.{{cite journal |last1=Stemmerik |first1=Lars |last2=Bendix-Almgreen |first2=Svend E. |last3=Piasecki |first3=Stefan |year=2001 |title=The Permian-Triassic boundary in central East Greenland: past and present views |journal=Bulletin of the Geological Society of Denmark |volume=48 |pages=159–167 |doi=10.37570/bgsd-2001-48-09|doi-access=free }}
Geology
Following Surlyk et al., 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{{cite journal |last=Nielsen |first=Eigil |author-link=Eigil Nielsen (paleontologist) |year=1935 |title=The Permian and Eotriassic vertebrate-bearing beds at Godthaab Gulf (East Greenland) |journal=Meddelelser om Grønland |volume=98 |issue=1 |pages=1–111}} recognized five fossil-bearing horizons ("fish zones 1–5"){{cite journal |last=Nielsen |first=Eigil |author-link=Eigil Nielsen (paleontologist) |year=1942 |title=Studies on Triassic fishes from East Greenland 1. Glaucolepis and Boreosomus |journal=Palaeozoologica Groenlandica |volume=1 |pages=1–403}}{{cite journal |last=Nielsen |first=Eigil |author-link=Eigil Nielsen (paleontologist) |year=1949 |title=Studies on Triassic fishes from East Greenland 2. Australosomus and Birgeria |journal=Palaeozoologica Groenlandica |volume=3 |pages=1–309}} 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.
The Kap Stosch Formation is subdivided into the following eight members (in ascending order):
- 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)
Paleobiota
A diverse vertebrate fauna composed of temnospondyl amphibians and fishes is known from the formation.{{cite journal |last1=Brinkmann |first1=Winand |last2=Romano |first2=Carlo |last3=Bucher |first3=Hugo |last4=Ware |first4=David |last5=Jenks |first5=Jim |year=2010 |title=Palaeobiogeography and stratigraphy of advanced gnathostomian fishes (Chondrichthyes and Osteichthyes) in the Early Triassic and from selected Anisian localities (Report 1863–2009) |journal=Zentralblatt für Geologie und Paläontologie, Teil II |volume=2009 |pages=765–812 |url=https://www.zora.uzh.ch/id/eprint/34071/1/Brinkmann_et_al2010_Palaeobiogeography%20and%20Stratigraphy%20of%20Advanced%20Gnathostomian%20Fishes%20in%20the%20Early%20Triassic%20and%20from%20selected%20Anisian%20Localities-2.pdf}}. Fossil fishes are also known from the Permian Ravnefjeld Formation ("Posidonomya shale") of Greenland.
=Amphibians=
{{paleobiota-key-compact}}
=Fish=
==Lobe-finned==
{{paleobiota-key-compact}}
| class="wikitable" align="center" | ||||
| colspan="5" align="center" | Sarcopterygii of the Wordie Creek Formation | ||||
|---|---|---|---|---|
| Taxon / Genus | Species | Subunit | Notes | Images |
| rowspan="2" |Laugia
|L. groenlandica |Kap Stosch Formation, Pyramiden Member ("Fish zones 2–3") | A laugiid coelacanth | rowspan="5" |File:Laugia.jpg]] | ||||
| Laugia sp. | ||||
| Sassenia
|S. groenlandica |? |A rhabdodermatid coelacanth{{cite book |last=Forey |first=Peter L. |year=1998 |title=History of the coelacanth fishes |publisher=Chapman & Hall |location=London |pages=434 |isbn=9780412784804}} that was originally referred to as Sassenia sp. The genus is also known from the Vikinghøgda Formation of Spitsbergen | ||||
| style="background:#fbdddb;"|Whiteia
|style="background:#fbdddb;"|W. nielseni |style="background:#fbdddb;"|? |style="background:#fbdddb;"|A whiteiid coelacanth that was originally described as Whiteia sp. and "undetermined coelacanth". The genus Whiteia had a cosmopolitan distribution during the Triassic |
==Ray-finned==
{{paleobiota-key-compact}}
| class="wikitable" align="center" | ||||
| colspan="5" align="center" | Actinopterygii of the Wordie Creek Formation | ||||
|---|---|---|---|---|
| Taxon / Genus | Species | Subunit | Notes | Images |
| rowspan="4" |Australosomus
|A. kochi |Kap Stosch Formation, Pyramiden Member ("Fish zones 2–4") and Falkeryg Member ("Fish zone 5") |A pholidopleuriform neopterygian. The genus had a cosmopolitan distribution during the Early Triassic epoch | rowspan="20" |File:Birgeria recon.jpg]] | ||||
| A. simplex
|Kap Stosch Formation (Pyramiden Member, "Fish zone 2") |A pholidopleuriform neupterygian. The genus had a cosmopolitan distribution during the Early Triassic epoch | ||||
| A. aff. ''simplex
|Kap Stosch Formation, Falkeryg Member ("Fish zone 5") |A pholidopleuriform neupterygian. The genus had a cosmopolitan distribution during the Early Triassic epoch | ||||
| A. pholidopleuroides
|Kap Stosch Formation (Pyramiden Member, "Fish zone 2") |A pholidopleuriform neupterygian. The genus had a cosmopolitan distribution during the Early Triassic epoch | ||||
| Birgeria
|B. groenlandica |Kap Stosch Formation, Pyramiden Member ("Fish zone 2"), Falkeryg Member ("Fish zone 5") |A birgeriid. The genus had a cosmopolitan distribution during the Triassic | ||||
| rowspan="2" |Bobasatrania
|B. groenlandica |Kap Stosch Formation, Pyramiden Member ("Fish zones 2–3") |A bobasatraniform{{cite journal |last=Nielsen |first=Eigil |author-link=Eigil Nielsen (paleontologist) |year=1952 |title=A preliminary note on Bobasatrania groenlandica |journal=Meddelelser Fra Dansk Geologisk Forening |volume=12 |issue=12 |pages=197–204 |url=https://2dgf.dk/xpdf/bull-1952-12-2-197-204.pdf}} The genus had a cosmopolitan distribution during the Triassic | ||||
| Bobasatrania sp.
|A bobasatraniform. One of the few Permian occurrences of the genus | ||||
| Boreosomus
|B. piveteaui |Kap Stosch Formation, Pyramiden Member ("Fish zones 2–4"), Falkeryg Member ("Fish zone 5") |A ptycholepid. The genus had a cosmopolitan distribution during the Early Triassic epoch | ||||
| Broughia
|B. perleididoides |Kap Stosch Formation, Pyramiden Member ("Fish zone 3"), Falkeryg Member ("Fish zone 5") |A parasemionotiform neopterygian | ||||
| Helmolepis
|H. gracilis |Kap Stosch Formation, Pyramiden Member ("Fish zones 2–4") |A platysiagid neopterygian. The genus had a cosmopolitan distribution during the Early Triassic{{cite journal |last=Nybelin |first=Orvar |year=1977 |title=Studies on Triassic fishes from East Greenland III. On Helmolepis gracilis Stensiö |journal=Meddelelser om Grønland |volume=200 |pages=1–13}} | ||||
| Ospia
|O. whitei |Kap Stosch Formation, Pyramiden Member ("Fish zone 3"), Falkeryg Member ("Fish zone 5") |A parasemionotiform neopterygian | ||||
| rowspan="6" style="background:#fbdddb;"|Pteronisculus
|style="background:#fbdddb;"|P. arcticus |style="background:#fbdddb;"|Kap Stosch Formation, Pyramiden Member ("Fish zone 2") |style="background:#fbdddb;"|A rhadinichthyid or turseoid, It was originally described as Glaucolepis arctica, but later referred to the genus Pteronisculus because the genus name Glaucolepis is preoccupied | ||||
| style="background:#fbdddb;"|P. aldingeri
|style="background:#fbdddb;"|Kap Stosch Formation, Pyramiden Member ("Fish zones 2 and 4") |style="background:#fbdddb;"|A rhadinichthyid or turseoid, It was originally described as Glaucolepis aldingeri, but later referred to the genus Pteronisculus because the genus name Glaucolepis is preoccupied | ||||
| style="background:#fbdddb;"|P. gunnari
|style="background:#fbdddb;"|Kap Stosch Formation, Pyramiden Member ("Fish zones 2?–3") |style="background:#fbdddb;"|A rhadinichthyid or turseoid, It was originally described as Glaucolepis gunnari, but later referred to the genus Pteronisculus because the genus name Glaucolepis is preoccupied | ||||
| style="background:#fbdddb;"|P. magnus
|style="background:#fbdddb;"|Kap Stosch Formation, Falkeryg Member ("Fish zone 5") |style="background:#fbdddb;"|A rhadinichthyid or turseoid, It was originally described as Glaucolepis magna, but later referred to the genus Pteronisculus because the genus name Glaucolepis is preoccupied | ||||
| style="background:#fbdddb;"|P. stensioei
|style="background:#fbdddb;"|Kap Stosch Formation, Falkeryg Member ("Fish zone 5") |style="background:#fbdddb;"|A rhadinichthyid or turseoid, It was originally described as Glaucolepis stensioei, but later referred to the genus Pteronisculus because the genus name Glaucolepis is preoccupied | ||||
| style="background:#fbdddb;"|Pteronisculus sp.
|style="background:#fbdddb;"|Kap Stosch Formation, Pyramiden Member ("Fish zones 2–4"), Godthåb Golf Formation ("Stegocephalian horizon") |style="background:#fbdddb;"|A rhadinichthyid or turseoid, It was originally referred to the genus Glaucolepis, a homonym of Pteronisculus | ||||
| rowspan="2" |Saurichthys
|S. aff. dayi |Kap Stosch Formation, Pyramiden Member ("Fish zone 2"), Falkeryg Member ("Fish zone 5"){{cite journal |last=Kogan |first=Ilja |year=2011 |title=Remains of Saurichthys (Pisces, Actinopterygii) from the Early Triassic Wordie Creek Formation of East Greenland |journal=Bulletin of the Geological Society of Denmark |volume=59 |pages=93–100 |issn=0011-6297 |doi=10.37570/bgsd-2011-59-09 |doi-access=free}} |A saurichthyiform with a dense squamation | ||||
| S. cf. ornatus{{cite book |last1=Mutter |first1=Raoul J. |last2=Cartanyà |first2=Joan |last3=Basaraba |first3=Susan A. U. |year=2008 |chapter=New evidence of Saurichthys from the Lower Triassic with an evaluation of early saurichthyid diversity |title=Mesozoic fishes 4. Homology and phylogeny |editor1=G. Arratia |editor2=H.-P. Schultze |editor2-link=Hans-Peter Schultze |editor3=M. V. H. Wilson |pages=103–127 |publisher=Dr. Friedrich Pfeil |location=München}}
|Kap Stosch Formation, Falkeryg Member ("Fish zone 5") |A three-dimensionally preserved skull of a saurichthyiform, which was analyzed using μCT-aided tomography{{Cite journal |last1=Argyriou |first1=Thodoris |last2=Giles |first2=Sam |author-link2=Sam Giles |last3=Friedman |first3=Matt |last4=Romano |first4=Carlo |last5=Kogan |first5=Ilja |last6=Sánchez-Villagra |first6=Marcelo R. |year=2018 |title=Internal cranial anatomy of Early Triassic species of †Saurichthys (Actinopterygii: †Saurichthyiformes): implications for the phylogenetic placement of †saurichthyiforms |journal=BMC Evolutionary Biology |volume=18 |issue=1 |pages=161 |doi=10.1186/s12862-018-1264-4 |issn=1471-2148 |pmc=6211452 |pmid=30382811 |doi-access=free }} | ||||
| style="background:#fbdddb;"|Teffichthys
|style="background:#fbdddb;"|T. stoschiensis |style="background:#fbdddb;"|Kap Stosch Formation, Pyramiden Member ("Fish zones 2–4"), Falkeryg Member ("Fish zone 5") |style="background:#fbdddb;"|A perleidiform neopterygian. It was originally described as Perleidus stoschiensis. Early Triassic species of Perleidus were subsequently referred to the genus Teffichthys{{Cite journal |author1=Marramà, G. |author2=Lombardo, C. |author3=Tintori, A. |author4=Carnevale, G. |name-list-style=amp |year=2017 |title=Redescription of "Perleidus"(Osteichthyes, Actinopterygii) from the Early Triassic of northwestern Madagascar. |journal=Rivista Italiana di Paleontologia e Stratigrafia |volume=123 |issue=2 |pages=219–242 |doi=10.13130/2039-4942/8328|doi-access=free}} |
==Cartilaginous==
{{paleobiota-key-compact}}
| class="wikitable" align="center" | ||||
| colspan="5" align="center" | Chondrichthyes of the Wordie Creek Formation | ||||
|---|---|---|---|---|
| Taxon / Genus | Species | Subunit | Notes | Images |
| Polyacrodus
|P. claveringensis |Kap Stosch Formation, Pyramiden Member ("Fish zone 2") |A polyacrodontid hybodontiform shark. Known from isolated teeth and partial skeletons with fin spines | rowspan="4" |File:Hybodus hauffianus.png]] | ||||
| Nemacanthus?
|N.? sp. | ||||
| Edestidae
|Gen. et sp. indet |Kap Stosch Formation, Pyramiden Member ("Fish zone 2") |Symphyseal tooth whorl of a eugeneodontid holocephalian | ||||
| Hybodontiformes
|Gen. et sp. indet |
See also
{{Portal|Earth sciences|Paleontology}}
References
{{Reflist}}
- {{cite web|title= Fossilworks: Gateway to the Paleobiology Database|author= ((Various Contributors to the Paleobiology Database))|url= https://www.fossilworks.org|access-date= 17 December 2021}}
Category:Paleontology in Greenland