Early ontogenetic growth stages of Middle Ordovician orthoceratoid cephalopods from Bohemia

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F20%3A00541388" target="_blank" >RIV/67985831:_____/20:00541388 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11310/20:10422826 RIV/00023272:_____/20:10134957

Výsledek na webu

<a href="https://www.app.pan.pl/article/item/app007212020.html" target="_blank" >https://www.app.pan.pl/article/item/app007212020.html</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.4202/app.00721.2020" target="_blank" >10.4202/app.00721.2020</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Early ontogenetic growth stages of Middle Ordovician orthoceratoid cephalopods from Bohemia

Popis výsledku v původním jazyce

This study describes 18 specimens representing the earliest growth parts of orthoceratoid cephalopods, most of which have been recently obtained from the Middle Ordovician strata of the Prague Basin, central Bohemia. Only about 20 specimens of Ordovician orthoceratoids displaying embryonic shell are known globally and the Bohemian material thus significantly expands their current record. The studied collection includes twelve specimens assigned to the species Bactroceras sandbergeri and shows that the morphological variability in early ontogenetic growth stages of this species was rather low. The absence of a cicatrix was definitely confirmed in this phylogenetically important cephalopod. Six other specimens investigated herein are indeterminate orthoceratids. Initial chambers, where preserved, are generally large compared to known, stratigraphically younger specimens. This is interpreted here as supporting the previously postulated trend of decreasing the egg- and hatchling sizes in orthoceratoid cephalopods from mid-Ordovician times onwards. Alternatively, the large sizes of these Bohemian orthoceratids may be explained by the position of the Prague Basin in relatively cool-water high palaeolatitudes during the Middle Ordovician.

Název v anglickém jazyce

Early ontogenetic growth stages of Middle Ordovician orthoceratoid cephalopods from Bohemia

Popis výsledku anglicky

This study describes 18 specimens representing the earliest growth parts of orthoceratoid cephalopods, most of which have been recently obtained from the Middle Ordovician strata of the Prague Basin, central Bohemia. Only about 20 specimens of Ordovician orthoceratoids displaying embryonic shell are known globally and the Bohemian material thus significantly expands their current record. The studied collection includes twelve specimens assigned to the species Bactroceras sandbergeri and shows that the morphological variability in early ontogenetic growth stages of this species was rather low. The absence of a cicatrix was definitely confirmed in this phylogenetically important cephalopod. Six other specimens investigated herein are indeterminate orthoceratids. Initial chambers, where preserved, are generally large compared to known, stratigraphically younger specimens. This is interpreted here as supporting the previously postulated trend of decreasing the egg- and hatchling sizes in orthoceratoid cephalopods from mid-Ordovician times onwards. Alternatively, the large sizes of these Bohemian orthoceratids may be explained by the position of the Prague Basin in relatively cool-water high palaeolatitudes during the Middle Ordovician.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

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OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

Acta Palaeontologica Polonica

ISSN

0567-7920

e-ISSN

1732-2421

Svazek periodika

65

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

PL - Polská republika

Počet stran výsledku

14

Strana od-do

575-588

Kód UT WoS článku

000572534600011

EID výsledku v databázi Scopus

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