Ellipsocephalus

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Genus of trilobites (blind)

title: "Ellipsocephalus" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["ellipsocephalidae", "ptychopariida-genera", "cambrian-trilobites", "fossils-of-the-czech-republic", "paleozoic-life-of-new-brunswick", "cambrian-genus-extinctions"] description: "Genus of trilobites (blind)" topic_path: "general/ellipsocephalidae" source: "https://en.wikipedia.org/wiki/Ellipsocephalus" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Genus of trilobites (blind) ::

| fossil_range = Middle Cambrian | image = Ellipsocephalus_Hoffi.jpg | image_caption = Ellipsocephalus hoffi, Cambrian, Jince Formation, Czech Republic | taxon = Ellipsocephalus | authority = Zenker, 1833 | subdivision_ranks = Species | subdivision = {{Species list |E. hoffi|(Schlotheim, 1823) = Trilobites hoffi |E. polytomus|(Linnarsson, 1877) |E. sanctacrucensis|(Samsonovicz, 1959) |E. vetustus|(Pompeckj, 1895)}}

Ellipsocephalus Zenker, 1833, is a genus of blind Cambrian trilobite, comprising benthic species inhabiting deep, poorly lit or aphotic habitats. E. hoffi is a common trilobite mainly from central Europe (Czech Republic).

::figure[src="https://upload.wikimedia.org/wikipedia/commons/2/22/Ellipsocephalus_sanctacrucensis.jpg" caption="''Ellipsocephalus sanctacrucensis''"] ::

Distribution

  • Ellipsocephalus hoffi (Schlotheim, 1823) SCHLOTHEIM, E.F., 1823. Nachträge zur Petrefactenkunde. Zw. Abteilung, Becker, Gotha, 114 pp. occurs in the Middle Cambrian of the Czech Republic, Jince Formation, Ellipsocephalus hoffi–Paradoxides (Rejkocephalus)–Lingulella Biozone of Fatka & Szabad (2014).
  • Ellipsocephalus polytomus Linnarsson, 1877,LINNARSSON, G., 1877. Om faunan i lagren med Paradoxides ölandicus. Geologiska Föreningens i Stockholm Förhandlingar, 3, pp. 352 – 375 is widely distributed in the ‘Oelandicus Beds’ (Baltoparadoxides oelandicus Biosuperzone) of Sweden and found near Viken, Näkten lake, Närke and Jämtland. The species is also known from drill cores retrieved from the island of Gotland, Sweden (e.g., Ahlberg 1989).
  • Ellipsocephalus sanctacrucensis (Samsonowicz, 1959) is known from the Middle Cambrian of Poland (Słowiec Sandstone Formation, Paradoxides insularis and P. pinus-zones, near Brzechów, Holy Cross Mountains).

Description

Ellipsocephalus is approximately oval in shape and markedly convex. It has opistoparian facial sutures that are directed slightly outward from both front and back of the eyes. The glabella has approximately parallel, slightly concave sides and is rounded frontally. Lateral furrows are indiscernible, as is the occipital ring. The palpebral lobes are not distinctly separated from the narrow occular ridges. The preglabellar field is somewhat inflated and librigenae are half as wide as the fixigenae. Some species have genal spines (as in E. sanctacrucensis), whereas in the most common species (E. hoffi) the genae lack spines and are only slightly angular posterolaterally. Ellipsocephalus has 12 thoracic segments and the pygidium is four times wider than long.

Behaviour

Ellipsocephalus and some other primitive micropygous Cambrian genera, such as Bailiella, enroll differently from other trilobites so that the posterior thorax segments and pygidium bend under the thorax. This is called "double enrollment".

References

Sources

References

  1. ZENKER, J. C., 1833. ''Beiträge zur Naturgesichte der Urwelt. Organische Reste (Petrefacten) aus der Altenbruger BraunkohlenFormation, dem Blankenburger Quadersandstein, Jenaischen bunten Sandstein und Böhmischen Uebergangsgebirge''. Friedrich Mauke, Jena, '''67'''
  2. "Trends in benthic trilobites".
  3. "Jince formation".
  4. FATKA, O. & SZABAD, M., 2014. Biostratigraphy of Cambrian in the Příbram-Jince Basin (Barrandian area, Czech Republic). ''Bulletin of Geosciences'', '''88''', 413–429.
  5. S.M. GON III. "Trilobites of the Jince Formation, Czech Republic".
  6. AHLBERG, P., 1989. Cambrian stratigraphy of the När 1 deep well, Gotland. ''Geologiska Föreningens i Stockholm Förhandlingar'', '''111''', 137–148.
  7. (2007). "The Middle Cambrian paradoxidid trilobite ''Hydrocephalus'' from Jämtland, central Sweden". Acta Geologica Polonica.
  8. SAMSONOWICZ, J. 1959a. On Strenuaeva from Lower Cambrian in Klimontów Anticlinorium. ´ Bulletin de l’Académie Polonaise des Sciences, Série des sciences chimiques, géologiques et géographiques. '''7''', pp. 521 – 4.
  9. SAMSONOWICZ, J. 1959b. On Strenuella and Germaropyge from the Lower Cambrian in the Klimontów Anticlinorium. Bulletin de l’Academie Polonaise des Sciences, Série des sciences chimiques, géologiques et géographiques, '''7''', 525 – 9.
  10. (1994). "Burgess shale-type fossils in Cambrian sandstones of the Holy Cross Mountains". Acta Palaeontologica Polonica.
  11. MOORE, R. C.. (1959). "Arthropoda I - Arthropoda General Features, Proarthropoda, Euarthropoda General Features, Trilobitomorpha". Geological Society of America/University of Kansas Press.

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ellipsocephalidaeptychopariida-generacambrian-trilobitesfossils-of-the-czech-republicpaleozoic-life-of-new-brunswickcambrian-genus-extinctions