Myriapod divergence times differ between molecular clock and fossil evidence: U/Pb zircon ages of the earliest fossil millipede-bearing sediments and their significance

Brookfield, Michael E.; Catlos, Elizabeth J.; Suarez, S. E.

doi:10.1080/08912963.2020.1762593

Cited by 10 publications

(7 citation statements)

References 40 publications

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“…These ages are also indistinguishable from the weighted mean of the concordant SIMS ages (421.7 ± 10.8 Ma for sample 17b/4 and 420.5 ± 21.4 Ma for sample 14c). We note that Brookfield et al (2020) indicated a 420 Ma age for this unit based on the SIMS results. However, the CA-ID-TIMS ages reported here should be considered more precise and used for constraining the timing of maximum deposition.…”

mentioning

confidence: 73%

“…Both U-Pb secondary ion mass spectrometry (SIMS) and chemical abrasion isotope dilution thermal ionization mass spectrometry (CA-ID-TIMS) techniques were used to date zircon. The results have implications for understanding the timing of major biotic events in Earth history and establishing the stratigraphy of the latest stages of the Silurian (Brookfield et al 2020).…”

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confidence: 93%

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Late Silurian zircon U–Pb ages from the Ludlow and Downton bone beds, Welsh Basin, UK

Catlos

Mark

Suarez

et al. 2020

JGS

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The Ludlow Bone Bed (Welsh Basin) is a critical stratigraphic horizon and contains a rich assemblage of fish scales. Units above provide insights into the early evolution of animal and plant life. The bed has not yet been radioisotopically dated. Here, we report 207 secondary ion mass spectrometry (SIMS) ages from 102 zircon (ZrSiO4) grains from the Ludlow (n = 2) and stratigraphically higher Downton (n = 1) bone beds. SIMS ages are middle Ordovician (471.6 ± 20.7 Ma) to late Devonian (375.7 ± 14.6 Ma, 238U–206Pb, ±1σ analytical uncertainty). Cathodoluminescence images show that the youngest ages appear affected by alteration. Chemical abrasion isotope dilution thermal ionization mass spectrometry (CA-ID-TIMS) U–Pb geochronology was utilized to improve precision. Detrital zircon grains from Downton yield 424.91 ± 0.34/0.42/0.63 Ma and from Ludlow 424.85 ± 0.32/0.41/0.62 Ma (n = 5 each, 238U–206Pb, ±2σ analytical, tracer or systematic uncertainty). These ages provide a maximum deposition age. Results overlap the basal Přídolí age (423.0 ± 2.3 Ma) in its stratotype (Požáry Section, Reporyje, Prague, Czech Republic). The Ludlow Bone Bed marks the base of the local Downton Group, which has previously been correlated with the base of the Přídolí Series. The CA-ID-TIMS ages are older than those for other land arthropod-bearing sediments, such as the Cowie Harbour Fish Bed and Rhynie Chert.Supplementary material: An Excel file containing detailed information on the SIMS analyses, a figure showing calibration curves for AS3 standards sputtered over sessions 1 and 2, and a figure showing CA-ID-TIMS U–Pb age data (concordia and weighted mean plots) are available at https://doi.org/10.6084/m9.figshare.c.5087031

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confidence: 73%

mentioning

confidence: 93%

Late Silurian zircon U–Pb ages from the Ludlow and Downton bone beds, Welsh Basin, UK

Catlos

Mark

Suarez

et al. 2020

JGS

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“…Any of these can be confidently considered to be the oldest terrestrial arthropod body fossils, albeit the fidelity of their preservation does not permit the observation of anatomical adaptations for life on land—most are represented by small shreds of cuticle or, in the case of Eotarbus , a dark carbonised specimen. U-Pb zircon dating of the Ludlow bone bed at Ludford Lane in Shropshire constrained the age of the deposit to ~420 Ma [ 63 ].…”

Section: Origin and Terrestrialization Of Arthropodsmentioning

confidence: 99%

“…This phylogenetic position is hardly reconcilable with a marine origin of scorpions, suggesting that some of these ancestral scorpions may have secondarily returned to the aquatic environment, although without obvious marine adaptations. The earliest member of Trigonotarbida, a group of extinct terrestrial arachnids known to possess book lungs [ 140 , 141 ], is known from the Silurian (~420 Ma [ 63 ]) Ludford Lane in England [ 59 ]. Trigonotarbids persisted until the Permian and are known in stunning anatomic detail, in part thanks to their preservation in Rhynie chert [ 142 ]).…”

Section: Pre-devonian Fossil Record Of Terrestrial Arthropodsmentioning

confidence: 99%

Was There a Cambrian Explosion on Land? The Case of Arthropod Terrestrialization

Tihelka

Howard

Cai

et al. 2022

Biology

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Arthropods, the most diverse form of macroscopic life in the history of the Earth, originated in the sea. Since the early Cambrian, at least ~518 million years ago, these animals have dominated the oceans of the world. By the Silurian–Devonian, the fossil record attests to arthropods becoming the first animals to colonize land, However, a growing body of molecular dating and palaeontological evidence suggests that the three major terrestrial arthropod groups (myriapods, hexapods, and arachnids), as well as vascular plants, may have invaded land as early as the Cambrian–Ordovician. These dates precede the oldest fossil evidence of those groups and suggest an unrecorded continental “Cambrian explosion” a hundred million years prior to the formation of early complex terrestrial ecosystems in the Silurian–Devonian. We review the palaeontological, phylogenomic, and molecular clock evidence pertaining to the proposed Cambrian terrestrialization of the arthropods. We argue that despite the challenges posed by incomplete preservation and the scarcity of early Palaeozoic terrestrial deposits, the discrepancy between molecular clock estimates and the fossil record is narrower than is often claimed. We discuss strategies for closing the gap between molecular clock estimates and fossil data in the evolution of early ecosystems on land

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“…As common soil macro-invertebrates, millipedes of the arthropods are one of the oldest terrestrial organisms and are widely distributed, with the earliest millipede fossils dating back to the late Silurian [ 11 ]. Millipedes contribute to soil processes, maintaining the soil fertility of mountain forests [ 12 , 13 , 14 ].…”

Section: Introductionmentioning

confidence: 99%

Genetic Diversity and Population Structure of Spirobolus bungii as Revealed by Mitochondrial DNA Sequences

Chen

Pan

et al. 2022

Insects

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Soil macrofauna, such as Spirobolus bungii, are an important component of ecosystems. However, systematic studies of the genetic diversity, population genetic structure, and the potential factors affecting the genetic differentiation of S. bungii are lacking. We performed a population genetic study of 166 individuals from the mountains to the south of the Yangtze River, north of the Yangtze River in Nanjing city, and near Tianjin city, in order to investigate the correlations between geographical distance and genetic diversity. A total of 1182 bp of COX2 and Cytb gene sequences of mitochondrial DNA, and 700 bp of the 18S rRNA gene sequence were analyzed. There were two haplotypes and one variable site in the 18S rRNA gene, and 28 haplotypes and 78 variable sites in the COX2 and Cytb genes. In this study, the 18S rRNA gene was used for species identification, and mtDNA (concatenated sequences with Cytb and COX2) was used for population genetic analysis. Structure cluster analysis indicated that the genetic structures of the different populations of S. bungii tended to be consistent at small geographical scales. Phylogenetic trees revealed that the haplotypes were clearly divided into three branches: the area south of the Yangtze River, the area to the north of the Yangtze River in Nanjing, and the area in Tianjin. Large geographical barriers and long geographical distance significantly blocked gene flow between populations of S. bungii. Our results provide a basic theoretical basis for subsequent studies of millipede taxonomy and population genetic evolution.

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Myriapod divergence times differ between molecular clock and fossil evidence: U/Pb zircon ages of the earliest fossil millipede-bearing sediments and their significance

Cited by 10 publications

References 40 publications

Late Silurian zircon U–Pb ages from the Ludlow and Downton bone beds, Welsh Basin, UK

Late Silurian zircon U–Pb ages from the Ludlow and Downton bone beds, Welsh Basin, UK

Was There a Cambrian Explosion on Land? The Case of Arthropod Terrestrialization

Genetic Diversity and Population Structure of Spirobolus bungii as Revealed by Mitochondrial DNA Sequences

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