Javascript är avstängt eller blockerat i din webbläsare. Detta kan leda till att vissa delar av vår webbplats inte fungerar som de ska. Sätt på javascript för optimal funktionalitet och utseende.

Webbläsaren som du använder stöds inte av denna webbplats. Alla versioner av Internet Explorer stöds inte längre, av oss eller Microsoft (läs mer här: * https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Var god och använd en modern webbläsare för att ta del av denna webbplats, som t.ex. nyaste versioner av Edge, Chrome, Firefox eller Safari osv.

Mats Eriksson

Mats Eriksson

Professor

Mats Eriksson

Ghosts from the past - ancestral features reflected in the jaw ontogeny of the polychaetous annelids Marphysa fauchaldi (Eunicidae) and Diopatra aciculata (Onuphidae)

Författare

  • Hannelore Paxton
  • Mats Eriksson

Summary, in English

Species of Eunicida (polychaetous annelids) have complex jaw apparatuses with ventral mandibles growing throughout life, but dorsal maxillae undergoing successive moulting episodes. Jaw ontogeny was studied in the eunicid Marphysa fauchaldi, from the appearance of the mandibles and larval maxillae through two moults during the transformation to juvenile and sub-adult maxillae. Although larval maxillae have been previously known, this is the first description of the juvenile stage for Eunicidae. The immature maxillary stages of M. fauchaldi were compared with those of Diopatra aciculata of the sister family Onuphidae, and, in a novel approach, extended deep into the fossil record by searching among adult stages of extinct eunicidans. Although neither the larval nor the juvenile stage resembles any complete fossil apparatus, each stage has features of separate maxillae known from different geological times. The larval maxilla II of both species is similar to the jaws of the Early Ordovician xanioprinids, the juvenile maxilla I of D. aciculata strikingly resembles those of the adult Palaeozoic Atraktoprion, whereas that of M. fauchaldi resembles those of Brochosogenys and allies. Thus, the extant taxa analysed represent cases in which ontogeny recapitulates phylogeny. It may also suggest that onuphid jaws are closer to the ancestral state than those of eunicids. This study opens a new perspective on evolutionary patterns, discusses asymmetry in jaw apparatuses relating to the basal plate concept, the apparent absence of early ontogenetic stages from the fossil record and cautions the use of architectural types in the interpretation of fossil maxillary apparatuses.

Avdelning/ar

  • Berggrundsgeologi

Publiceringsår

2012

Språk

Engelska

Sidor

309-316

Publikation/Tidskrift/Serie

GFF

Volym

134

Issue

4

Dokumenttyp

Artikel i tidskrift

Förlag

Taylor & Francis

Ämne

  • Geology

Nyckelord

  • Eunicida
  • jaw apparatus
  • Labidognatha
  • mandibles
  • maxillae
  • moulting

Status

Published

ISBN/ISSN/Övrigt

  • ISSN: 2000-0863