A new agnostoid from the Cambrian of Scandinavia Tomagnostella tullbergi n. sp. (Agnostidae) from the middle Cambrian Lejopyge laevigata Zone of Scandinavia
DOI | 10.37570/bgsd-2024-73-11 |
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Aasta | 2024 |
Ajakiri | Bulletin of the Geological Society of Denmark |
Köide | 73 |
Leheküljed | 193-198 |
Tüüp | artikkel ajakirjas |
Keel | inglise |
Id | 50326 |
Abstrakt
A rare new agnostoid species, Tomagnostella tullbergi n. sp., is described from the lower part of the middle Cambrian Lejopyge laevigata Zone in Scandinavia, corresponding to the lower part of the Guzhangian global Stage. The species is currently known only from the Andrarum Limestone Bed of Skåne, southernmost Sweden, and coeval strata in the Oslo Region, Norway; it has also been recorded from ice-rafted Andrarum Limestone found in Germany. The material assigned to T. tullbergi n. sp. has previously been confused with Tomagnostella exsculpta. The new species is characterized by a cephalon with a moderately angular glabellar front (distinctly angular in T. exsculpta) and a pygidium with a narrow, pointed axis showing a depressed tip; a small secondary node is located within this depression close to the tip of the axis (in T. exsculpta the axis is broad and rounded posteriorly and without a posterior depression; a minute terminal node may or may not be present). Tomagnostella tullbergi n. sp. is also comparatively large-sized whereas T. exsculpta attains smaller maximum sizes.