A microscopic Burgess Shale: small carbonaceous fossils from a deeper water biota and the distribution of Cambrian non-mineralized faunas DOI Creative Commons
Giovanni Mussini, Nicholas J. Butterfield

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2025, Volume and Issue: 292(2041)

Published: Feb. 1, 2025

(SCFs) have disclosed a record of organically preserved faunas from Cambrian epeiric seas. Their phylogenetically and functionally derived components, including probable crown-group crustaceans molluscs, are absent the ‘exceptional’ palaeoenvironmental settings captured by Burgess Shale-type (BST) macrofossil biotas. This apparent segregation SCF BST-macrofossil deposits has led to contrasting hypotheses on whether their faunal differences reflect genuine ecological patterns or overriding taphonomic controls. We report new, exceptionally diverse biota Hess River Formation Northwest Territories (Canada), which occupied an offshore slope setting. The biota, hosted single shale sample, rivals Shale in its disparity bilaterian body plans, providing microfossil counterpoint regional similar deeper-water palaeoenvironments. SCFs comprise ecdysozoan spiralian sclerites, arthropod mouthparts, semi-articulated wiwaxiids, problematica pterobranchs, but no recognizable crown molluscs crustaceans. similarities between fauna classic biotas suggest significant palaeoecological overlap, robust distinct expressions. upholds existence comparatively modern communities settings, populating both assemblages sampling

Language: Английский

Exotic cuticular specializations in a Cambrian scalidophoran DOI Creative Commons
Giovanni Mussini, Nicholas J. Butterfield

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2025, Volume and Issue: 292(2040)

Published: Feb. 1, 2025

Scalidophora, the ecdysozoan group including priapulids, kinorhynchs and loriciferans, comprises some of most abundant ecologically important Cambrian animals. However, reconstructions morphology lifestyles fossil scalidophorans are often hampered by poor preservation their submillimetre-scale cuticular specializations. Based on exceptionally preserved small carbonaceous fossils (SCFs), we describe a new scalidophoran-grade animal, Scalidodendron crypticum gen. et sp. nov., from Early to Middle Hess River Formation northern Canada. The SCFs comprise pharyngeal teeth, coniform sclerites hook-like sclerites, all closely comparable known scalidophoran counterparts. recurrently associate with arborescent projections that show multiple orders branching, morphologically unlike those any living or scalidophoran. fine splintering inferred post-pharyngeal position these structures argue against locomotory, feeding defensive roles direct analogues in extant As such, denote previously cryptic range morphological variation scalidophorans, paralleling coeval panarthropods but expressed at fundamentally different level anatomical organization.

Language: Английский

Citations

2
A microscopic Burgess Shale: small carbonaceous fossils from a deeper water biota and the distribution of Cambrian non-mineralized faunas DOI Creative Commons
Giovanni Mussini, Nicholas J. Butterfield

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2025, Volume and Issue: 292(2041)

Published: Feb. 1, 2025

(SCFs) have disclosed a record of organically preserved faunas from Cambrian epeiric seas. Their phylogenetically and functionally derived components, including probable crown-group crustaceans molluscs, are absent the ‘exceptional’ palaeoenvironmental settings captured by Burgess Shale-type (BST) macrofossil biotas. This apparent segregation SCF BST-macrofossil deposits has led to contrasting hypotheses on whether their faunal differences reflect genuine ecological patterns or overriding taphonomic controls. We report new, exceptionally diverse biota Hess River Formation Northwest Territories (Canada), which occupied an offshore slope setting. The biota, hosted single shale sample, rivals Shale in its disparity bilaterian body plans, providing microfossil counterpoint regional similar deeper-water palaeoenvironments. SCFs comprise ecdysozoan spiralian sclerites, arthropod mouthparts, semi-articulated wiwaxiids, problematica pterobranchs, but no recognizable crown molluscs crustaceans. similarities between fauna classic biotas suggest significant palaeoecological overlap, robust distinct expressions. upholds existence comparatively modern communities settings, populating both assemblages sampling

Language: Английский

Citations

1