Evidence map›Paper›PMID 39968616›Full record

ArticleProceedings. Biological sciences2025

Cambrian carbonaceous protoconodonts and the early fossil record of the Chaetognatha.

Ben J Slater

Abstract read
In one paragraph

Article in Proceedings. Biological sciences, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

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2 · The registry

The trial behind it

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3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
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4 · The record

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5 · Who and what money

Authors and funding

1 author.

Ben J SlaterDepartment of Earth Sciences, Palaeobiology, Uppsala University, Uppsala, Sweden.ORCID 0000-0002-5774-9114

Funding

Vetenskapsrådet
6 · The paper itself

Abstract

Fossil remains from the early Cambrian Period suggest an ancient origin for the phylum Chaetognatha. As macrofossils, Cambrian chaetognaths are restricted to just a few Konservat-Lagerstätten sites, yet the dispersed grasping spines characteristic of this clade are relatively common as phosphatized 'protoconodonts'. Here, an abundance of protoconodonts are described, but preserved in an entirely different manner, as 'small carbonaceous fossils' (SCFs) extracted from Cambrian Fortunian and Stage 4 mudrocks of Estonia and Sweden, respectively. Preservation among small carbonaceous fossils is substantial, representing an alternative but overlooked resource for tracing the origins of the chaetognath clade. Importantly, small carbonaceous fossils are abundant in normal marine siliciclastic deposits, in which conventionally studied phosphatic protoconodont fossils are scarce. Recent advances in constraining the phylogenetic position of chaetognaths suggest a relationship to the clade Gnathifera (gnathostomulids, micrognathozoans, rotifers). Newly emerging small carbonaceous fossil records, therefore, offer the chance to establish important calibration points for the divergence of deep bilaterian clades, including Protostomia, Lophotrochozoa and Gnathifera. Protoconodonts are especially valuable in this respect given their appearance close to, or prior to, the Ediacaran-Cambrian boundary. A first compilation of small carbonaceous fossil protoconodont records suggests chaetognath-like bilaterians had evolved by the latest Ediacaran (approximately 555-545 Ma), while the jaw complex possessed by the chaetognath crown-group emerged at least 520 Ma.

Indexed as

Biological EvolutionFossilsInvertebratesAnimalsEstoniaPhylogenySwedenBilateriaCambrianChaetognathaEdiacaranGnathiferaprotoconodontsmall carbonaceous fossils

Identifiers

PMID39968616
PMCPMC11836706

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