Evidence map›Paper›PMID 42490452›Full record

ArticleScience advances2026

Earth's magnetic field remained weak for 40 million years after the Cambrian radiation.

Simon J Lloyd, Andrew J Biggin, Rebecca Hopkins, Alexander Tully, Brendan Cych, Greig A Paterson, Ricardo Trindade

Abstract read
In one paragraph

Article in Science advances, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Simon J LloydDepartment of Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, UK.ORCID 0000-0001-6986-4892
Andrew J BigginDepartment of Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, UK.ORCID 0000-0003-4164-5924
Rebecca HopkinsDepartment of Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, UK.
Alexander TullyDepartment of Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, UK.ORCID 0000-0003-4371-0523
Brendan CychDepartment of Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, UK.ORCID 0000-0003-2387-3544
Greig A PatersonDepartment of Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, UK.ORCID 0000-0002-6864-7420
Ricardo TrindadeUniversity of Sao Paulo, Sao Paulo, Brazil.ORCID 0000-0001-9848-9550

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The Ediacaran-Cambrian interval marks major environmental change and the emergence of complex life, coinciding with some of the weakest magnetic field strengths in Earth history. It has been proposed that inner core nucleation near this boundary triggered a rapid strengthening of the geodynamo during the early Cambrian, but direct constraints on magnetic field behavior across this interval remain limited. Here, we present new paleointensity results from two Cambrian igneous sequences in Brazil (~525 million years ago) and Nova Scotia (~505 million years ago). Using multiple complementary methods, both records indicate a reversing geomagnetic field that remained weak. Combined with a reanalysis of published data, our results show that weak magnetic field conditions persisted for tens of millions of years after the Cambrian radiation. These findings limit the magnitude and timing of any Cambrian geodynamo strengthening and imply that Earth's magnetospheric shielding remained strongly suppressed during a key phase of early animal evolution.

Identifiers

PMID42490452
PMCPMC13394383

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.