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| 2. |
- Schoenemann, Brigitte, et al.
(författare)
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A Tiny Eye Indicating A Planktonic Trilobite
- 2010
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Ingår i: Palaeontology. - : Wiley. - 1475-4983 .- 0031-0239. ; 53:4, s. 695-701
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Tidskriftsartikel (refereegranskat)abstract
- Cambrian trilobites mainly lived on the sea floor, and up till now few, if any, unequivocally planktonic trilobites have been reported from earlier than the Ordovician. The late Cambrian (Furongian) to late Ordovician olenids are a distinctive group of benthic (sea-floor dwelling) or nekto-benthic trilobites. Here we show, however, that one recently described, miniaturized and very spiny olenid species, Ctenopyge ceciliae must have been planktonic ( passively drifting or feebly swimming in the upper waters of the sea). This interpretation is based not only upon body form but also on the analysis of its visual system and may be one of the earliest records of the planktonic realm being invaded by trilobites.
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| 3. |
- Stewart, Sarah Elizabeth, et al.
(författare)
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Sphenothallus from the Furongian (Cambrian) of Scandinavia
- 2015
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Ingår i: GFF. - : Informa UK Limited. - 2000-0863 .- 1103-5897. ; 137:1, s. 20-24
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Tidskriftsartikel (refereegranskat)abstract
- Sphenothallus, a Palaeozoic genus of uncertain affinity, possibly a hydrozoan, is reported from the Furongian (Cambrian) of Scandinavia. This is the only known occurrence of the genus in Cambrian rocks outside of China, western North America and Bohemia, and also the first report of Sphenothallus in the Cambrian-Ordovician of Baltica. The material is from the upper Furongian (upper Protopeltura and lower Peltura superzones) of Mount Kinnekulle, Vastergotland, south-central Sweden. It consists of elongated, slightly tapering, shiny black phosphatic tubules. Scanning electron microscope photographs confirm paired internal longitudinal thickenings, typical of the genus, on opposite sides of the central lumen. The presence of the Swedish material in a low-energy, dysoxic facies is consistent with most previous occurrences.
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