Biology:Exigua
| Exigua | |
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| Superfamily: | Raymondinacea
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| Subfamily: | Raymondininae
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| Genus: | Exigua Howell, 1937
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Brassicicephalus | |
Exigua (synonym: Brassicicephalus) is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived from 501 to 497 million years ago during the Dresbachian faunal stage of the late Cambrian Period.[3] Exigua is only known from the central part of the headshield or cranidium, so free cheeks (or librigenae), thorax and pygidium are unknown.
Etymology
Exigua, is Latin meaning small, meager or sparse, referring to the small size of the only parts known of these trilobites, namely the cranidia. The synonym Brassicicephalus is a combination of Brassica (Latin, "cabbage") and κεφαλή, kephalē (Greek: "head") for the strongly convex glabella and fixed cheeks separated by a deep furrow.
References
- ↑ Robison, R.A. (1988). Peel, J.S.. ed. Trilobites of the Holm Dal Formation (late Middle Cambrian), central North Greenland. Mededelser om Grønland - Geoscience. 20. pp. 94–96. ISBN 8763511908. https://books.google.com/books?id=9GihNpPF8fgC&pg=PA94.
- ↑ Lochman, C.; Duncan, D. (1944). "Early Upper Cambrian Faunas of Central Montana". Geological Society of America Special Papers 54: 13. doi:10.1130/spe54-p1. ISBN 0813720540. https://books.google.com/books?id=Eq367lcmK3MC&pg=PA23.
- ↑ Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (Trilobita entry)". Bulletins of American Paleontology 364: 560. Archived from the original on 2006-09-05. https://web.archive.org/web/20060905162524/http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=307&rank=class. Retrieved 2008-01-12.
Wikidata ☰ Q4957946 entry
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