Early post-embryonic development in Ellipsostrenua (Trilobita, Cambrian, Sweden) and the developmental patterns in Ellipsocephaloidea

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F18%3A00499752" target="_blank" >RIV/67985831:_____/18:00499752 - isvavai.cz</a>

Alternative codes found

RIV/00023272:_____/18:10134106

Result on the web

<a href="http://dx.doi.org/10.1017/jpa.2018.25" target="_blank" >http://dx.doi.org/10.1017/jpa.2018.25</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1017/jpa.2018.25" target="_blank" >10.1017/jpa.2018.25</a>

Result language

angličtina

Original language name

Early post-embryonic development in Ellipsostrenua (Trilobita, Cambrian, Sweden) and the developmental patterns in Ellipsocephaloidea

Original language description

This study documents the early post-embryonic developmental stages (protaspides and early meraspides) of the Cambrian trilobite Ellipsostrenua granulosa (Ahlberg, 1984) from the Gardsjon Formation of Jamtland, Sweden. The early protaspid stage is characterized by a circular outline of the exoskeleton, two pairs of fixigenal spines, a short preglabellar field, a genal swelling, and prominent bacullae. The late protaspid stage differs only in having the trunk portion discernible. Early meraspid cranidia are sub-rectangular with prominent palpebral lobes, a wide anterior margin, a proportionally long anterior branch of the facial suture, and intergenal spines. Meraspid pygidia tentatively assigned to this species possess comparatively long macrospines. Small hypostomes associated with E. granulosa bear at least four pairs of marginal spines. A comparison of the early developmental stages of E. granulosa with some other species of Ellipsocephalidae and with species of the closely related Estaingiidae reveals several similarities. The conservative morphology of the early protaspid stage with only two pairs of fix igenal spines, the timing of the development of the trunk portion, and the presence of genal swellings and prominent bacullae could be phylogenetically informative. The range of size variation of the early protaspid stages in two families may be related either to taxonomical differences between Ellipsocephalidae and Estaingiidae, or to environmental differences in various paleogeographic settings.

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

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2018

Confidentiality

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

Name of the periodical

Journal of Paleontology

ISSN

0022-3360

e-ISSN

—

Volume of the periodical

92

Issue of the periodical within the volume

6

Country of publishing house

US - UNITED STATES

Number of pages

20

Pages from-to

1018-1027

UT code for WoS article

000449392500005

EID of the result in the Scopus database

2-s2.0-85055223143