Authors

N. Robin,corresponding author1 P. Gueriau,2 J. Luque,3 D. Jarvis,1 A. C. Daley,2 and R. Vonk4,5

Affiliations

1School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork T23N73K, Ireland
2Institute of Earth Sciences, University of Lausanne, Géopolis, 1015 Lausanne, Switzerland
3Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
4Department of Taxonomy and Systematics, Naturalis Biodiversity Center, 9517, 2300 RA Leiden, The Netherlands
5Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, 94240, 1090 GE Amsterdam, The Netherlands

Topic

Cell Biology

Abstract

Peracarida (e.g. woodlice and side-swimmers) are, together with their sister-group Eucarida (e.g. krill and decapods), the most speciose group of modern crustaceans, suggested to have appeared as early as the Ordovician. While eucarids' incursion onto land consists of mainly freshwater and littoral grounds, some peracarids have evolved fully terrestrial ground-crawling ecologies, inhabiting even our gardens in temperate regions (e.g. pillbugs and sowbugs). Their fossil record extends back to the Carboniferous and consists mainly of marine occurrences. Here, we provide a complete re-analysis of a fossil arthropod—Oxyuropoda—reported in 1908 from the Late Devonian floodplains of Ireland, and left with unresolved systematic affinities despite a century of attempts at identification. Known from a single specimen preserved in two dimensions, we analysed its anatomy using digital microscopy and multispectral macroimaging to enhance the contrast of morphological structures. The new anatomical characters and completeness of Oxyuropoda, together with a phylogenetic analysis with representatives of all major Eumalacostraca groups, indicate that Oxyuropoda is a crown peracarid, part of a clade including amphipods and isopods. As such, Oxyuropoda is the oldest known species Peracarida, and provides evidence that derived peracarids had an incursion into freshwater and terrestrial environments as early as the Famennian, more than 360 Ma.


DOI: https://dx.doi.org/10.1098%2Frsbl.2021.0226

Extract

Illumination is provided by 16 LED lights ranging from 365 up to 700 nm wavelength (CoolLED pE-4000), coupled to a liquid light-guide fibre fitted with a fibre-optic ring light-guide.

Product Associated Features

The pE-4000 Universal Illumination System offers 16 selectable wavelengths from 365 - 770 nm, making it a highly flexible illuminator to cover more than 90 pairs for illumination/detection in this application.

Product Type

pE-4000

Journal

Biol Lett.

Year of Publication

2021

Country of Publication

Ireland, Switzerland, USA