小油櫛蟲

小油栉虫属; 化石时期：522–510 Ma PreЄ Є O S D C P T J K Pg N 寒武紀
	Olenellus thompsoni
科学分类
界：	动物界 Animalia
门：	节肢动物门 Arthropoda
纲：	†三叶虫纲 Trilobita
目：	†莱得利基虫目 Redlichiida
科：	†小油栉虫科 Olenellidae
亚科：	†小油栉虫亚科 Olenellinae
属：	†小油栉虫属 Olenellus; Billings（英语：Elkanah Billings）, 1861
模式種
	Olenellus thompsoni; (Hall（英语：James Hall (paleontologist)）, 1859)
種
	見內文

小油櫛蟲（學名：Olenellus）是生存於寒武紀第二世第四期的一屬三葉蟲，是目前發現最古老的三葉蟲品種之一。這類原始的三葉蟲生活在海底，不怎麼活躍。牠們的尾部較小，頭及眼大，並有眾多長有棘刺的胸節，其中一節特別顯眼。胸部呈錐狀、往後逐漸變小。頭甲周圍有一圈窄小的縫，與頰刺連成一體。外骨骼的護膜很薄。牠們沒有背部表面的骨縫——這是其他三葉蟲擁有的特徵。^[1]

物種

Olenellus agellus Resser & Howell, 1938^[2]
Olenellus chiefensis Palmer（英语：Allison R. Palmer）, 1998^[3]
Olenellus clarki (Resser, 1928),^[2] 異名 Paedeumias clarki
Olenellus crassimarginatus Walcott, 1910,^[2] 異名 O. thompsoni crassimarginatus, O. wanneri, O. latilimbatus
Olenellus fowleri Palmer, 1998^[3]
Olenellus getzi Dunbar（英语：Carl Owen Dunbar）, 1925,^[2] 異名 O. alius, O. peculiaris
Olenellus howelli Meek（英语：Fielding Bradford Meek）, 1874^[3]
Olenellus nevadensis (Walcott, 1910),^[2] 異名 Paedeumias nevadensis, Callavia nevadensis
Olenellus parvofrontatus Fritz, 1991^[2]
Olenellus puertoblancoensis Lochman, 1952^[2]
Olenellus robsonensis Burling, 1916,^[2] 異名 Paedeumias robsonensis
Olenellus roddyi Resser & Howell, 1938,^[2] 異名 O. similaris, O. nodosus, O. nitidus, O. jonasae, Paedeumias glabrum, P. yorkense, P. eboracense
Olenellus romensis Resser & Howell, 1938,^[2] 異名 O. buttsi
Olenellus terminatus Palmer, 1998^[3]
Olenellus thompsoni (Hall（英语：James Hall (paleontologist)）, 1859)^[2]^[4]
Olenellus transitans (Walcott, 1910),^[2] 異名 O. brachycephalus, Paedeumias perkinsi

重新分配的物種

以下的物種現時已被置入其他屬。

Olenellus alabamensis = Fremontella halli
Olenellus altifrontatus = Bolbolenellus altifrontatus
Olenellus argentus^[5] pl. 40, fig 12, 13, 15, 16, non fig. 14 = Grandinasus argentus
Olenellus argentus^[5] pl. 40, fig 14, non fig. 12, 13, 15, 16 = Holmiella falx
Olenellus bondoni = Fallotaspis bondoni
Olenellus bonnensis = Mesonacis bonnensis
Olenellus brevoculus = Mesonacis bonnensis
Olenellus broegeri = Callavia broegeri
Olenellus bristolensis = Bristolia bristolensis
Olenellus bristolensis^[6] p. 8. fig 1-11, non pl. 7, fig 1, 2, 5 = Bristolia harringtoni
Olenellus bufrontis = Bolbolenellus sphaerulosus
Olenellus callavei = Callavonia callavei
Olenellus cylindricus = Mesonacis cylindricus
Olenellus eagerensis = Mesonacis eagerensis
Olenellus euryparia = Bolbolenellus euryparia
Olenellus forresti = Redlichia forresti
Olenellus fremonti^[5] pl. 15, fig. 18 = Bristolia fragilis
Olenellus fremonti^[5] pl. 37, fig. 1, 4-5 = Bolbolenellus euryparia
Olenellus fremonti^[5] pl. 37, fig. 1-2 = Mesonacis fremonti
Olenellus georgiensis,^[7] p. 220, pl. 5, fig. 7, non fig. 6 = Mesonacis vermontanus
Olenellus gigas = Andalusiana cornuta
Olenellus gilberti = Bristolia bristolensis
Olenellus groenlandicus = Bolbolenellus groenlandicus
Olenellus halli = Fremontella halli
Olenellus hamoculus = Mesonacis hamoculus
Olenellus hermani = Bolbolenellus hermani
Olenellus hyperboreus = Mesolenellus hyperboreus
Olenellus insolens = Bristolia insolens
Olenellus intermedius = Fritzolenellus lapworthi or F. reticulatus
Olenellus kentensis = Bolbolenellus groenlandicus
Olenellus lapworthi = Fritzolenellus lapworthi
Olenellus laxocules = Elliptocephala laxocules
Olenellus logani = Elliptocephala logani
Olenellus mickwitzi = Schmidtiellus mickwitzi mickwitzi
Olenellus mohavensis = Bristolia mohavensis
Olenellus multinodus = Nephrolenellus multinodus
Olenellus paraocules = Elliptocephala paraocules
Olenellus praenuntius = Elliptocephala praenuntius
Olenellus reticulatus = Fritzolenellus reticulatus
Olenellus sequomalus = Elliptocephala sequomalus
Olenellus sphaerulosus = Bolbolenellus sphaerulosus
Olenellus svalbardensis = Mesolenellus svalbardensis
Olenellus terranovicus = Mesonacis bonnensis
Olenellus torelli = Schmidtiellus mickwitzi torelli
Olenellus truemani^[8] = Elliptocephala walcotti
Olenellus truemani^[9] = Fritzolenellus truemani
Olenellus truncatooculatus = Mummaspis truncatooculatus
Olenellus vermontanus = Mesonacis vermontanus
Olenellus walcottanus = Wanneria walcottana

圖片

Olenellus thompsoni的復原圖
Olenellus fowleri
Olenellus fowleri
吉伯特氏小油櫛蟲（Olenellus gilberti）
Olenellus roddyi
Olenellus chiefensis
Olenellus clarki
Olenellus nevadensis
Olenellus terminatus

參考文獻

^ Walker, Cyril; Ward, David. Fossils. Smithsonian Handbooks revised, illustrated. Dorling Kindersley. 2002: 56. ISBN 0789489848.
^ ^2.00 ^2.01 ^2.02 ^2.03 ^2.04 ^2.05 ^2.06 ^2.07 ^2.08 ^2.09 ^2.10 ^2.11 Lieberman, B.S. Systematic Revision of the Olenelloidea (Trilobita, Cambrian) (PDF). Bulletin of the Peabody Museum of Natural History. 1999, 45 [2017-11-29]. （原始内容存档 (PDF)于2016-06-24）.
^ ^3.0 ^3.1 ^3.2 ^3.3 Palmer, A.R. Terminal Early Cambrian Extinction of the Olenellina: Documentation from the Pioche Formation, Nevada. Journal of Paleontology. 1998, 72 (4): 650–672. JSTOR 1306693.
^ Cowie, J.; McNamara, K.J. Olenellus (Trilobita) from the Lower Cambrian Strata of North-West Scotland (PDF). Palaeontology. 1978, 21 (3): 615–634 [2017-11-29]. （原始内容存档 (PDF)于2012-05-26）.
^ ^5.0 ^5.1 ^5.2 ^5.3 ^5.4 Walcott, C.D., Olenellus and other genera of the Mesonacidae, Smithsonian Miscellaneous Collections, 1910, 63 (6): 231–422
^ Riccio, J.F., The Lower Cambrian Olenellidae of the Marble Mountains, California, Bulletin of the Californian Academy of Sciences, 1952, 51: 25–49
^ Resser, C.E.; Howell, B.F., Lower Cambrian Olenellus zone of the Appalachians, Bulletin of the Geological Society of America, 1938, 49: 195–248
^ Fritz, W.H., Lower Cambrian Trilobites from the Sekwi Formation type section, Mackenzie Mountains, northwestern Canada, Bulletin of the Canadian Geological Survey, 1972, 212: 1–90
^ Walcott, C.D., Cambrian geology and paleontology, No. 11, New Lower Cambrian subfauna, Smithsonian Miscellaneous Collections, 1913, 67 (11): 309–326

外部連結

Olenellus in the Paleobiology Database（英语：Paleobiology Database）
photograph of Olenellus chiefensis （页面存档备份，存于互联网档案馆）
photograph of Olenellus getzi
photograph of Olenellus gilberti
photograph of Olenellus terminatus （页面存档备份，存于互联网档案馆）
photograph of Olenellus thompsoni
photograph of Olenellus transitans

[1] Walker, Cyril; Ward, David. Fossils. Smithsonian Handbooks revised, illustrated. Dorling Kindersley. 2002: 56. ISBN 0789489848.

[Lieberman_1999-2] 2.00 ^2.01 ^2.02 ^2.03 ^2.04 ^2.05 ^2.06 ^2.07 ^2.08 ^2.09 ^2.10 ^2.11 Lieberman, B.S. Systematic Revision of the Olenelloidea (Trilobita, Cambrian) (PDF). Bulletin of the Peabody Museum of Natural History. 1999, 45 [2017-11-29]. （原始内容存档 (PDF)于2016-06-24）.

[Palmer-3] 3.0 ^3.1 ^3.2 ^3.3 Palmer, A.R. Terminal Early Cambrian Extinction of the Olenellina: Documentation from the Pioche Formation, Nevada. Journal of Paleontology. 1998, 72 (4): 650–672. JSTOR 1306693.

[Cowie&McNamara-4] Cowie, J.; McNamara, K.J. Olenellus (Trilobita) from the Lower Cambrian Strata of North-West Scotland (PDF). Palaeontology. 1978, 21 (3): 615–634 [2017-11-29]. （原始内容存档 (PDF)于2012-05-26）.

[Walcott,_1910-5] 5.0 ^5.1 ^5.2 ^5.3 ^5.4 Walcott, C.D., Olenellus and other genera of the Mesonacidae, Smithsonian Miscellaneous Collections, 1910, 63 (6): 231–422

[Riccio-6] Riccio, J.F., The Lower Cambrian Olenellidae of the Marble Mountains, California, Bulletin of the Californian Academy of Sciences, 1952, 51: 25–49

[Resser_&_Howell-7] Resser, C.E.; Howell, B.F., Lower Cambrian Olenellus zone of the Appalachians, Bulletin of the Geological Society of America, 1938, 49: 195–248

[Fritz,_1972-8] Fritz, W.H., Lower Cambrian Trilobites from the Sekwi Formation type section, Mackenzie Mountains, northwestern Canada, Bulletin of the Canadian Geological Survey, 1972, 212: 1–90

[Walcott,_1913-9] Walcott, C.D., Cambrian geology and paleontology, No. 11, New Lower Cambrian subfauna, Smithsonian Miscellaneous Collections, 1913, 67 (11): 309–326

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