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Mats Eriksson

Mats Eriksson

Professor

Mats Eriksson

The beginning of a success story : basalmost members of the extant ophiuroid clade from the Silurian of Gotland, Sweden

Författare

  • Ben Thuy
  • Mats E. Eriksson
  • Manfred Kutscher
  • Lea D. Numberger-Thuy

Summary, in English

Due to the fragility of the ophiuroid (brittle star) skeleton, the bulk of the group’s fossil record consists of dissociated ossicles preserved as microfossils. In spite of their great potential as basis for taxonomic and phylogenetic studies, however, ophiuroid ossicles from the Paleozoic have received very little attention so far. Here, we provide an exhaustive taxonomic assessment of such fossils retrieved from sieving residues from the Silurian of Gotland, Sweden. This material was used in a previous study to describe two key taxa that allowed constraining the origin of the extant ophiuroid clade. The remaining taxa belonging to that same lineage are described in the present paper. The evidence at hand suggests that the stem of the extant ophiuroid clade was formed by two genera, Ophiopetagno and Ophiolofsson gen. nov., including six and five species, respectively, and spanning at least the upper Llandovery through upper Ludlow. We conclude that Ophiopetagno and Ophiolofsson represent sister genera that coexisted through most of the Silurian in the shallow tropical seas of Gotland. They underwent repeated body size reductions in correlation with environmental perturbations, with Ophiopetagno paicei eventually giving rise to Muldaster haakei; the first member of the living Ophiuroidea. Herein, we also introduce two new clades, Ankhurida clade nov. and Ophiovalida clade nov., and the following eight new species: Ophiolofsson joelmciveri gen. et sp. nov., O. obituary gen. et sp. nov., O. immolation gen. et sp. nov., O. archspire gen. et sp. nov., O. hendersonorum gen. et sp. nov., Ophiopetagno bonzo sp. nov., O. kansas sp. nov., O. doro sp. nov.; and two probably new species in open nomenclature: Ophiopetagno sp. 1, and Ophiopetagno sp. 2.

Avdelning/ar

  • Geologiska institutionen
  • Berggrundsgeologi

Publiceringsår

2024-07

Språk

Engelska

Sidor

216-247

Publikation/Tidskrift/Serie

European Journal of Taxonomy

Volym

947

Dokumenttyp

Artikel i tidskrift

Förlag

Museum National d'Histoire Naturelle

Ämne

  • Geology

Nyckelord

  • Ankhurida
  • Gotland
  • new species
  • Ophiovalida
  • Phylogeny

Aktiv

Published

ISBN/ISSN/Övrigt

  • ISSN: 2118-9773