Ontogeny, muscle scars, colour pattern and predation marks in a Silurian orthoceratid cephalopod

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00023272%3A_____%2F25%3A10136909" target="_blank" >RIV/00023272:_____/25:10136909 - isvavai.cz</a>

Alternative codes found

RIV/00025798:_____/25:10169732

Result on the web

<a href="https://www.app.pan.pl/article/item/app012432025.html" target="_blank" >https://www.app.pan.pl/article/item/app012432025.html</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.4202/app.01243.2025" target="_blank" >10.4202/app.01243.2025</a>

Result language

angličtina

Original language name

Ontogeny, muscle scars, colour pattern and predation marks in a Silurian orthoceratid cephalopod

Original language description

Muscle scars, embryonic shell, colour pattern and intraspecific variation are known together in a very limited number of straight shelled cephalopods, leading to uncertainty in the classification of the subclass Orthoceratoidea. The newly described genus Lepidoceras from the Silurian of Bohemia, interpreted as a demersal orthoceratid similar to Kionoceras, shows all relevant diagnostic characters. The earliest late Wenlock populations of Lepidoceras have a weakly curved endogastric shell, but the shell becomes increasingly more curved throughout the Ludlow. The sculpture is characterized by distinctive longitudinal lirae or ridges, the number of which is variable and maintained during ontogeny. The embryonic shell of Lepidoceras is one of the largest in orthoceratids; it is conical or weakly curved in shape beginning with a smooth non-accretion initial shell. Hatching is manifested by growth walls in some specimens; hatchlings were apparently demersal. Adults are usually characterized by mature modifications of the shell: septal crowding and shell wall thickening. A high proportion of adult specimens indicates low mortality in palaeopopulations. Healed repairs indicate a lower predation pressure, which decreases after the juvenile stage. Extensive shell repair in juveniles demonstrates high regenerative capacity. Orthoceratomorph muscle scars found only in adults show a pair of dorsal retractor imprints that gradually expanded laterally. The colour pattern consists of irregular transverse bands, which have never been detected in orthoceratids before. The pattern, which is similar to that in curved oncocerids, is probably an expression of adaptive convergence of this feature in both groups. Shell pathologies, which have been observed in juvenile orthoceratids for the first time, are rare; an extensive pathology in a mature specimen illustrates limit of survival in orthoceratids.

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

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OECD FORD branch

10506 - Paleontology

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

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

Name of the periodical

Acta Palaeontologica Polonica

ISSN

0567-7920

e-ISSN

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Volume of the periodical

70

Issue of the periodical within the volume

3

Country of publishing house

PL - POLAND

Number of pages

25

Pages from-to

517-541

UT code for WoS article

001574237400007

EID of the result in the Scopus database

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