Condylopyge

Condylopyge
Temporal range: latest Lower to early Middle Cambrian (Toyonian to Mayaian)
Cephalon (top) and pygidium (bottom) of Condylopyge rex
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Trilobita
Order: Agnostida
Suborder: Agnostina
Superfamily: Condylopygoidea
Family: Condylopygidae
Genus: Condylopyge
Hawle & Corda, 1847
species
  • C. rex (Barrande, 1846) (type) synonyms Battus rex, Agnostus rex
  • C. amitina Rushton, 1966
  • C. antiqua Elicki & Pillola, 2004
  • C. blayaci (Howell, 1935) synonym Fallagnostus blayaci
  • C. carinata Westergård, 1936
  • C. cruzensis Liñan & Gozalo, 1986
  • C. eli Geyer, 1998
  • C. imperator Howell, 1935
  • C. matutina Dean, 2005
  • C. regia (Sjögren, 1872)
  • C. spinigera Westergård, 1941
  • C. vicina Egorova, 1972
Synonyms

Paragnostus, Fallagnostus

Condylopyge is a genus of very small trilobites, that lived during the latest Early and the early Middle Cambrian, in what are today Canada (Newfoundland and New Brunswick), Czech Republic, England and Wales, France, Germany, Italy, Morocco, the Russian Federation (North-East Siberia), Spain, Turkey and Sweden. It can easily be distinguished from all other Agnostida because the frontal lobe of the central raised area of the headshield (or glabella) is wider than the rear lobe. It looks like Pleuroctenium but the frontal glabellar lobe does not fold around the rear lobe, as it does in Pleuroctenium.

Distribution

Description

Like all Agnostida, Condylopyge is diminutive, with the headshield (or cephalon) and tailshield (or pygidium) of approximately the same size (or isopygous) and outline, and only two thorax segments. The characteristic sidewise expansion of the frontal lobe of the glabella, occipital structures instead of basal lobes, and a rhachis with three pairs of side lobes and a rear lobe differentiate Condylopygidae from all other agnostids. Condylopyge can easily be distinguished from its sister taxon Pleuroctenium because the frontal glabellar lobe does not wrap around the sides of the rear lobe, giving it a mushroom-like appearance. The frontal glabellar lobe is never dissected lengthwise, unlike in Pleuroctenium, where this is often clearly visible. The pygidium may carry a pair of backwardly directed spines, but this also occurs regularly in Pleuroctenium.[6]

References

  1. Mergl, M.; Elicki, O. (2004). "Cambrian lingulid and acrotretid brachiopods from the Iglesiente area (Campo Pisano Formation, southwestern Sardinia)". Rivista Italiana di Paleontologia e Stratigrafia 3 (110): 581–589.
  2. Howell, B. F. (1935). "Cambrian and Ordovician trilobites from Herault, southern France". Journal of Paleontology 3 (9): 222–238.
  3. Mykerinos. "Condylopyge cf. carinata". Forum des chercheurs de trilobites. Retrieved 20 May 2013.
  4. Garcia-Bellido, D. C.; Dies Alvarez, M. E.; Gamez Vintaned, J.A.; Linan, E.; Gozalo, R. (2011). "First report of Crumillospongia (Demospongea) from the Cambrian of Europe (Murero biota, Spain)". Bulletin of Geosciences 3 (86): 641–650. doi:10.3140/bull.geosci.1253.
  5. Dean, W.T. (2005). "Trilobites from the Çal Tepe Formation (Cambrian), near Seydişehir, Central Taurides, Southwestern Turkey" (PDF). Turkish Journal of Earth Sciences (Turkish J. Earth Sci.) (14): 1–71.
  6. 1 2 Whittington, H.B. et al. Part O, Treatise on Invertebrate Paleontology. Revised, Volume 1 – Trilobita – Introduction, Order Agnostida, Order Redlichiida. 1997
  7. Liñan, E.; Dies, M.E.; Vintaned, J.A.G.; Gozalo, R.; Mayoral, E.; Muñiz, F. (2005). "Lower Ovetian (Lower Cambrian) trilobites and biostratigraphy of the Pedroche Formation (Sierra de Córdoba, southern Spain)". Géobios 38: 365–381. doi:10.1016/j.geobios.2003.11.007.
  8. Geyer, G.; Landing, E. (2001). "Middle Cambrian of Avalonian Massachusetts: Stratigraphy and correlation of the Braintree trilobites". Journal of Paleontology 1 (75): 116–135. doi:10.1666/0022-3360(2001)075<0116:mcoams>2.0.co;2.
  9. Zamora, S.; Smith, A.B. (2008). "A new Middle Cambrian stem-group echinoderm from Spain: Palaeobiological implications of a highly asymmetric cinctan". Acta Palaeontologica Polonica 53: 207–220. doi:10.4202/app.2008.0204.

External links

This article is issued from Wikipedia - version of the Friday, August 07, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.