TY - JOUR

T1 - First record of an Early Ordovician brachiopod and conodont fauna from Lapland, Sweden

AU - Streng, Michael

AU - Rasmussen, Jan Audun

AU - Ebbestad, Jan Ove R.

AU - Weidner, Thomas

N1 - Publisher Copyright: © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.

PY - 2022

Y1 - 2022

N2 - An Early Ordovician fauna of linguliform brachiopods and euconodonts is described from the Alum Shale Formation in northernmost Västerbotten County, northern Sweden. The fauna was recovered from a single carbonate concretion collected at an exposure near the northern shore of Lake Storvindeln. Despite of the fragmentary and tectonized preservation of the obtained fossils, at least eight different taxa of linguliform brachiopods and four species of euconodonts could be identified. Among the brachiopods, the ephippelasmatid Pomeraniotreta biernatae Bednarczyk, 1986 is most common; it is associated among others with the acrotretids Eurytreta cf. sabrinae (Callaway, 1877) and Ottenbyella sp., and a spinose specimen potentially representing the zhanatellid Thysanotos. Two of the brachiopod taxa appear to present new species, Pomeraniotreta n. sp. and Mytoella? n. sp., but additional material would be needed for a formal description. Euconodont specimens are rare and comprise coniform elements of Drepanodus arcuatus Pander, 1856, Drepanoistodus aff. amoenus (Lindström, 1955) sensu Löfgren (1994), Paroistodus numarcuatus (Lindström, 1955) and Rossodus aff. manitouensis Repetski & Ethington, 1983. Evaluation of the stratigraphic distribution of the different taxa of brachiopods and euconodonts under consideration of the local geology, suggests that the investigated sample represents a level in the upper part of the Tremadocian (Tr2) part of the Alum Shale Formation. The fauna represents the northernmost occurrence of age diagnostic Early Ordovician (Tremadocian) fossils in Sweden.

AB - An Early Ordovician fauna of linguliform brachiopods and euconodonts is described from the Alum Shale Formation in northernmost Västerbotten County, northern Sweden. The fauna was recovered from a single carbonate concretion collected at an exposure near the northern shore of Lake Storvindeln. Despite of the fragmentary and tectonized preservation of the obtained fossils, at least eight different taxa of linguliform brachiopods and four species of euconodonts could be identified. Among the brachiopods, the ephippelasmatid Pomeraniotreta biernatae Bednarczyk, 1986 is most common; it is associated among others with the acrotretids Eurytreta cf. sabrinae (Callaway, 1877) and Ottenbyella sp., and a spinose specimen potentially representing the zhanatellid Thysanotos. Two of the brachiopod taxa appear to present new species, Pomeraniotreta n. sp. and Mytoella? n. sp., but additional material would be needed for a formal description. Euconodont specimens are rare and comprise coniform elements of Drepanodus arcuatus Pander, 1856, Drepanoistodus aff. amoenus (Lindström, 1955) sensu Löfgren (1994), Paroistodus numarcuatus (Lindström, 1955) and Rossodus aff. manitouensis Repetski & Ethington, 1983. Evaluation of the stratigraphic distribution of the different taxa of brachiopods and euconodonts under consideration of the local geology, suggests that the investigated sample represents a level in the upper part of the Tremadocian (Tr2) part of the Alum Shale Formation. The fauna represents the northernmost occurrence of age diagnostic Early Ordovician (Tremadocian) fossils in Sweden.

KW - euconodonts

KW - Lapland

KW - linguliform brachiopods

KW - Ordovician

KW - Tremadocian

U2 - 10.1080/11035897.2022.2032822

DO - 10.1080/11035897.2022.2032822

M3 - Journal article

AN - SCOPUS:85131525862

VL - 144

SP - 24

EP - 40

JO - G F F

JF - G F F

SN - 1103-5897

IS - 1

ER -