LARVAE & TRILOBITE ORDERS: CORYNEXOCHIDA

Undescribed

CLASSIFICATION & LARVAE:

Although the number of corynexochid protaspides described so far is rather limited, the early ontogeny of this group is well-known. Indeed, ana- and metaprotaspides of representatives of the three suborders have been described. This enables larval features differentiating the order Corynexochida as well as those characterizing its different suborders to be recognized.

Table 1. Classification scheme of the order Corynexochida (from Fortey, new Treatise, 1997 with minor modifications). Protaspid larvae of 6 (yellow & bold) of the 23 families have been described so far.

LOCALITIES:

1. Esbataottine Formation, Mackenzie Mts., Northwest Territories, Canada. MIDDLE ORDOVICIAN. 2. Road River Formation, Yukon Territory, Canada. SILURIAN. 3. Pika? Formation, Alberta, Canada. MIDDLE CAMBRIAN. 4. Mount Whyte Formation, Alberta, Canada. MIDDLE CAMBRIAN 5. Cathedral Formation, Alberta, Canada. MIDDLE CAMBRIAN. 6. Garden City Formation, Idaho, USA. EARLY ORDOVICIAN. 7. Edinburg Formation, Virginia, USA. MIDDLE ORDOVICIAN. 8. Kopanina Formations, Stredocesky, Czech Republic. SILURIAN. 9. Bissounel Formation, Montagne Noire, France. EARLY DEVONIAN. 10. Taemas Formation, New South Wales, Australia. EARLY DEVONIAN. 11. Currant Bush Limestone, Mt Drummond, Northern Territory, Australia. MIDDLE CAMBRIAN. 12. Balang Formation, Guizhou, China. EARLY CAMBRIAN. 13. Huangbailing Formation, Anhui, China. CAMBRIAN

ARTICLES:

NOTE: This list only concerns articles where protaspid larvae of corynexochid trilobites have been described or figured.

CHATTERTON, B.D.E. 1971. Taxonomy and ontogeny of Siluro-Devonian trilobites from near Yass, New South Wales. Palaeontographica (A), 137: 1-108. CHATTERTON, B.D.E. 1980. Ontogenetic studies of Middle Ordovician trilobites from the Esbataottine Formation, Mackenzie Mountains, Canada. Palaeontographica (A), 171: 1-74. FEIST, R. 1970. Breviscutellum (Meridioscutellum) n.sg. (Trilobite) et son developpement larvaire. Geobios, 3(4): 41-73. FORTEY, R.A. & B.D.E. CHATTERTON. 1988. Classification of the trilobite suborder Asaphina. Palaeontology, 31(1): 165-222.    pdf version HU, C.-H. 1970. Ontogenies and sexual dimorphisms of two Upper Cambrian trilobites. Proceedings of the Geological Society of China, 13: 143-155. HU, C.-H. 1971. Ontogeny and sexual dimorphism of Lower Paleozoic Trilobita. Palaeontographica Americana, 7(44): 29-155. HU, C.-H. 1974. Ontogenies of two Middle Ordovician from Edinburg Formation of Virginia. Transactions and proceedings of the Palaeontological Society of Japan (new series), 95: 353-363. HU, C.-H. 1976. Ontogenies of three species of silicified Middle Ordovician trilobites from Virginia. Transactions and proceedings of the Palaeontological Society of Japan (new series), 101: 247-263. HU, C.-H. 1985. Ontogenetic development of Cambrian trilobites from British Columbia and Alberta, Canada (Part I). Journal of Taiwan Museum, 38(2): 121-158. HU, C.-H. 1985. Ontogenies of two Middle Cambrian corynexochid trilobites from the Canadian Rocky Mountains. Transactions and Proceedings of the Palaeontological Society of Japan (new series), 138: 138-147. KACHA, P. & R. SARIC. 1991. Ontogeny of the trilobite Kosovopeltis svobodai Snadjr from the Bohemian Silurian. Vestnik Ustredniho Ustavu Geologickeho, 66: 257-273. LEE, D.-C. & B.D.E. CHATTERTON. 2003. Protaspides of Leiostegium and their implications for membership of the order Corynexochida. Palaeontology, 46(3): 431-445.    Abstract LU, Y. & Y. QIAN. 1983. Cambro-Ordovician trilobites from eastern Guizhou. Palaeontologia Cathayana, 1: 1-105. LUDVIGSEN, R. & B.D.E. CHATTERTON. 1980. The ontogeny of Failleana and the origin of the Bumastinae (Trilobita). Geological Magazine, 117(5): 471-478. LUDVIGSEN, R. & R.P. TRIPP. 1990. Silurian trilobites from the Northern Yukon Territory. Life Sciences Contributions (Royal Ontario Museum Toronto), 153: 1-59. MCNAMARA, K.J., F. YU, & Z. ZHIYI. 2003. Ontogeny and heterochrony in the Oryctocephalid trilobite Arthricocephalus from the Early Cambrian of China. Special papers in Palaeontology, 70: 103-126. MCNAMARA, K.J., F. YU, & Z. ZHIYI. 2003. Ontogeny and heterochrony in the Early Cambrian Oryctocephalid trilobites Changaspis, Duyunaspis and Balangia from China. Palaeontology, 49(1): 1-19. Abstract OPIK, A. A. 1982. Dolichometopid trilobites of Queensland, Northern Territory, and New South Wales. Australian Government Publishing Service, Bureau of Minrela Resources, Geology and Geophysics, Bulletin, 175: 1-85. RASETTI, F. 1967. Lower and Middle Cambrian faunas from the Taconic sequence of New York. Smithsonian Miscellaneous Collections, 152(4): 1-111. ROBISON, R.A. 1967. Ontogeny of Bathyuriscus fimbriatus and its bearing on the affinities of the corynexochid trilobites. Journal of Paleontology, 41(1): 213-221. ZHU, X.-J., & S.-C. PENG. 2004. Ontogeny of Cambrian trilobite Cheiruroides primigenius. Acta Palaeontologica Sinica, 43(1): 53-62.

For more general information about the Order Corynexochida, visit Sam Gon's Corynexochida Summary page

AGNOSTIDA

LICHIDA

PTYCHOPARIIDA

ASAPHIDA

PHACOPIDA

REDLICHIIDA

HARPETIDA

PROETIDA

(ASAPHIDA)

(HARPETIDA)

Last modified: Jan., 09th 2007

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