Early Middle Ordovician scolecodonts from north-western Argentina and the emergence of labidognath polychaete jaw apparatuses

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F17%3A00000086" target="_blank" >RIV/00025798:_____/17:00000086 - isvavai.cz</a>

Result on the web

<a href="http://onlinelibrary.wiley.com/doi/10.1111/pala.12303/full" target="_blank" >http://onlinelibrary.wiley.com/doi/10.1111/pala.12303/full</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/pala.12303" target="_blank" >10.1111/pala.12303</a>

Result language

angličtina

Original language name

Early Middle Ordovician scolecodonts from north-western Argentina and the emergence of labidognath polychaete jaw apparatuses

Original language description

Scolecodonts provide fossil evidence of the evolution and diversification of jaw-bearing polychaetes from the latest Cambrian onwards. However, their record before the Darriwilian (Middle Ordovician) is scarce worldwide, which limits our understanding of key evolutionary events. One such event is the emergence of taxa possessing the asymmetrical labidognath-type jaw apparatus architecture, which became common in the Middle Ordovician and is often dominant throughout the Palaeozoic. Here, we document a small collection of Dapingian scolecodonts from the Capillas section, Sierras Subandinas, north-western Argentina. The isolated elements recovered allowed us to reconstruct the distinctive jaw apparatus, and to introduce a new taxon, Andiprion paxtonae gen. et sp. nov. The maxillary apparatus of Andiprion is intermediate between the symmetrognath type of the Early Ordovician Kadriorgaspis and the labidognath type that is present in polychaetaspids and related taxa. The apparatus architecture of Andiprion corresponds best to the labidognath type, but the morphology of the individual jaws suggests that it may be the most primitive representative of this lineage currently known. We propose that Andiprion-like forms were ancestral to polychaetaspids, polychaeturids and ramphoprionids. The Capillas collection provides supporting evidence for the evolutionary homology of the ‘basal plate’ and the left first maxilla. Thus the labidognath-type asymmetry, with an unpaired left maxilla III, developed as a result of gradual reduction in size of the first right jaw (‘basal plate’) in front of the carriers, instead of loss or fusion of anterior maxillae.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10506 - Paleontology

Project

<a href="/en/project/GJ15-13525Y" target="_blank" >GJ15-13525Y: Early Palaeozoic jawed polychaete faunas and the impacts of environmental perturbations on the marine benthic ecosystem</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Palaeontology

ISSN

0031-0239

e-ISSN

—

Volume of the periodical

60

Issue of the periodical within the volume

4

Country of publishing house

GB - UNITED KINGDOM

Number of pages

11

Pages from-to

583-593

UT code for WoS article

000403326900011

EID of the result in the Scopus database

2-s2.0-85019669329