Biology:Genevievella

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Genevievella
Temporal range: Upper Cambrian
Genevievella granulosa CRF.jpg
Genevievella granulosa, 18mm
Scientific classification
Kingdom:
Phylum:
Class:
Order:
Superfamily:
Family:
Llanoaspididae
Genus:
Genevievella

Lochman, 1936
Type species
Genevievella neunia
Lochman, 1936
Synonyms[1]

Placosema Opik 1967

Genevievella is a genus of trilobites with a short inverted egg-shaped outline, a wide headshield, small eyes, and long genal spines. The backrim of the headshield is inflated and overhangs the first of the 9 thorax segments. The 8th thorax segment from the front bears a backward directed spine that reaches beyond the back end of the exoskeleton. It has an almost oval tailshield with 5 pairs of pleural furrows. It lived during the Upper Cambrian in what are today Canada and the United States.[2]

Distribution

  • G. caelata is known from the Upper Cambrian of Australia (Mindyallan, Upper beds Member, Mungerbar Formation, Glenormiston, Queensland, 22.9° S, 138.8° E).[3]
  • G. simon, G. cuniculaena, G. raggedi and G. campbellina have been found in the Upper Cambrian of Canada (Dresbachian, Rabbitkettle Formation, Yukon, 62.7° N, 128.4° W).[4]
  • G. campbellina occurs in the Upper Cambrian of the United States (Merioneth: Warriorsmark, Huntingdon, Huntingdon; Warrior Formation, near Waddle, Centre County, all Pennsylvania, 40.8° N, 77.9° W)[5]
  • G. spinox has been excavated from the Upper Cambrian of the United States (Dresbachian, Coosella zone, Riley Formation, Central Texas, 30.3° N, 97.7° W)[6]
  • G. bigranulosa is present in the Upper Cambrian of China (Guzhangian, Glyptagnostus stolidotus trilobite zone and Paibian, Glyptagnostus reticulatus trilobite zone, both Huaqiao Formation, Hunan, 28.4° N, 109.5° E).[7]

References

  1. "†Genevievella Lochmann 1936". Paleobiology Database. Fossilworks. http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon_no=20522. 
  2. Moore, R.C. (1959). Arthropoda I - Arthropoda General Features, Proarthropoda, Euarthropoda General Features, Trilobitomorpha. Treatise on Invertebrate Paleontology. Part O.. Boulder, Colorado/Lawrence, Kansas: Geological Society of America/University of Kansas Press. pp. O301. ISBN 0-8137-3015-5. 
  3. Pojeta, J.; Gilbert-Tomlinson, J.; Shergold, J.H. (1977). "Cambrian and Ordovician rostroconch molluscs from Northern Australia". Australian Bureau of Mineral Resources, Geology and Geophysics Bulletin 171: 1–54.  cited in Pete Wagner. "Locality 50. G127*. Glenormiston". http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&taxon_no=20522&max_interval=Cambrian&country=Australia&is_real_user=1&basic=yes&type=view&match_subgenera=1. 
  4. Pratt, B.R. (1992). "Trilobites of the Marjuman and Steptoean stages (Upper Cambrian), Rabbitkettle Formation, southern Mackenzie Mountains, northwest Canada". Palaeontographica Canadiana (9): 1–109.  cited in Shanan Peters. "Section N - collection N-33". http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&collection_no=55211. 
  5. Tasch, P. (1951). "Fauna and paleoecology of the Upper Cambrian Warrior Formation of central Pennsylvania". Journal of Paleontology 25 (3): 275–306.  cited in Uta Merkel. "Highway No. 322 near Waddle, Bed 11.12". http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&collection_no=77661. 
  6. Sepkoski Jr., J.J. (1998). "Rates of speciation in the fossil record". Philosophical Transactions of the Royal Society of London B: Biological Sciences 353 (1366): 315–326. doi:10.1098/rstb.1998.0212. PMID 11541734.  cited in Mike Sommers. "Central Texas, Riley Fm., Texas". http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&taxon_no=20522&max_interval=Cambrian&country=United_States&state=Texas&is_real_user=1&basic=yes&type=view&match_subgenera=1. 
  7. Peng, S.; Robison, R.A. (2000). "Agnostid biostratigraphy across the Middle-Upper Cambrian boundary in Hunan, China". Journal of Paleontology Memoir 53.  cited in Austin Hendy. "Paibi section, bed 37a". http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&collection_no=49187. 

Wikidata ☰ Q16981754 entry