orderphacopida

LARVAE & TRILOBITE ORDERS:
PHACOPIDA

from Edgecombe et al., 1998

CLASSIFICATION & LARVAE:

Protaspides of representatives of ten of the sixteen families have been described and, within each suborder, larvae of at least fifty percent of the families are known. Considering this, the early ontogeny of the Phacopida is probably the best known of all trilobite orders.

Table 1. Classification scheme of the order Phacopida (from Fortey, new Treatise, 1997). Protaspid larvae of 9 (yellow & bold) of the 16 families have been described so far.

PICTURES:

CALYMENINA:

Family CALYMENIDAE

Family HOMALONOTIDAE

CHEIRURINA:

Family CHEIRURIDAE

Family ENCRINURIDAE

Family PILEKIIDAE

Family PLIOMERIDAE

PHACOPINA:

Family PTERYGOMETOPIDAE

Family DALMANITIDAE

Family PROSOPISCIDAE

LOCALITIES:

1. Esbataottine Formation, Mackenzie Mts., NW Territories, Canada. MIDDLE ORDOVICIAN
2. Whittaker Formation, Mackenzie Mts., NW Territories, Canada. SILURIAN
3. Delorme Formation, Mackenzie Mts., NW Territories, Canada. SILURIAN
4. Broken Skull Formation, Mackenzie Mts., NW Territories, Canada. LOWER ORDOVICIAN
5. Garden City Formation, Idaho, USA. LOWER ORDOVICIAN
6. Garden City Formation, Utah, USA. LOWER ORDOVICIAN
7. Edinburg Formation, Virginia, USA. MIDDLE ORDOVICIAN
8. Martinsburg Formation, Virginia, USA. MIDDLE ORDOVICIAN
9. Sherman Fall Formation?, Virginia, USA. MIDDLE ORDOVICIAN
10. Crown Point Formation, New York, USA. MIDDLE ORDOVICIAN
11. Beechers Trilobite Beds, New York, USA. MIDDLE ORDOVICIAN
12. Hardwood Mountain Formation, Maine, USA. SILURIAN
13. Las Aguaditas Formation, San Juan Province, Argentina. MIDDLE / UPPER ORDOVICIAN
14. San Kuan Formation, San Juan Province, Argentina. LOWER / MIDDLE ORDOVICIAN
15. Vinice Formation, Bohemia, Czech Republic. ORDOVICIAN
16. Valhallfonna Formation, Ny Friesland, Spitsbergen. LOWER ORDOVICIAN
17. Nanchang Formation, Shaanxi Province, China. SILURIAN
18. Taemas Formation, New South Wales, Australia. LOWER DEVONIAN
19. Bissounel Formation, Montagne Noire, France. LOWER DEVONIAN

ARTICLES:

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

BARRANDE, J. 1852. Systeme Silurien du Centre de la Boheme. I. Recherches Paleontologiques, vol. 1 (Crustaces: Trilobites). Pragues & Paris. 935 p.
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.
CHATTERTON, B.D.E. & D.G. PERRY. 1984. Silurian cheirurid trilobites from the Mackenzie Mountains, northwestern Canada. Palaeontographica (A), 184: 1-78.
CHATTERTON, B.D.E., D.J., SIVETER, G.D., EDGECOMBE, & A. S. HUNT. 1990. Larvae and relationships of the Calymenina (Trilobita). Journal of Paleontology, 64(2): 255-277.
CRONIER, C. 2007. Larval morphology and ontogeny of an Upper Devonian Phacopid: Nephranops from Thuringia, Germany. Journal of Paleontology, 81(4): 684-700.    Abstract    NEW July
EDGECOMBE, G.D. & B.D.E. CHATTERTON. 1987. Heterochrony in the Silurian radiation of encrinurine trilobites. Lethaia, 20: 337-351.
EDGECOMBE, G.D. & B.D.E. CHATTERTON. 1990. Mackenziurus, a new genus of the Silurian "Encrinurus" variolaris plexus (Trilobita). American Museum Novitates, 2968: 1-22.   pdf version
EDGECOMBE, G.D. & B.D.E. CHATTERTON. 1992. Early Silurian (LLandovery) encrinurine trilobites from the Mackenzie Moutains, Canada. Journal of Paleontology, 66(1): 52-74.
EDGECOMBE, G.D., S.E., SPEYER, & B.D.E. CHATTERTON. 1988. Protaspid larvae and phylogenetics of encrinurid trilobites. Journal of Paleontology, 62(5): 779-799.
EDGECOMBE, G.D., B.D.E., CHATTERTON, N.E., VACCARI, & B.G. WAISFELD. 1999. Ordovician cheirurid trilobites from the Argentine precordillera. Journal of Paleontology, 73(6): 115-1175.    Abstract
EDGECOMBE, G.D., B.D.E., CHATTERTON, B.G., WAISFELD, & N.E. VACCARI. 1998. Ordovician (Whiterock) calymenid and encrinurid trilobites from the precordillera of Argentina. Journal of Paleontology, 72(4): 678-697.    Abstract Text
EDGECOMBE, G.D., B.D.E., CHATTERTON, B.G., WAISFELD, & N.E. VACCARI. 1999. Ordovician pliomerid and prosopiscid trilobites from Argentina. Journal of Paleontology, 73(6): 1144-1154.   Abstract    Text
EVITT, W.R. & R.P. TRIPP. 1977. Silicified Middle Ordovician trilobites from the families Encrinuridae and Staurocephalidae. Palaeontographica (A), 157: 109-174.
FORTEY, R.A. 1990. Ontogeny, hypostome attachment and trilobite classification. Palaeontology, 33: 529-576.    pdf version
FORTEY, R.A. & B.D.E. CHATTERTON. 1988. Classification of the trilobite suborder Asaphina. Palaeontology, 31(1): 165-222.    pdf version
FORTEY, R.A. & S.F. MORRIS. 1978. Discovery of a nauplius-like trilobite larvae. Palaeontology, 21(4): 823-833.    pdf version
HU, C.-H. 1971. Ontogeny and sexual dimorphism of Lower Paleozoic Trilobita. Palaeontographica Americana, 7(44): 29-155.
HU, C.-H. 1974. Ontogenies of a few Middle Ordovician trilobites from the Edinburg Formation of Virginia, USA. Bulletin of the Geological Survey of Taiwan, 24: 51-67.
HU, C.-H. 1975. Ontogenies of four species of silicified Middle Ordovician trilobites from Virginia. Proceedings of the Geological Society of China, 18: 115-127.
LEE, D.-C. & B.D.E. CHATTERTON. 1997. Ontogenies of trilobites from the Lower Ordovician Garden city formation of Idaho and their implications for the phylogeny of the Cheirurina. Journal of Paleontology, 71(4): 683-791.
LEROSEY-AUBRIL, R. 2007. Early Devonian calymenid larvae (Trilobita) from the Bissounel Formation (Montagne Noire, France). Bulletin de la Soci�t� G�ologique de France.    Abstract
LU, Y. & H. WU. 1982. The ontogeny of Platycoryphe sinensis and its bearing on the phylogeny of Homalonotidae. Acta Palaeontologica Sinica, 21: 37-56.
LU, Y. & H. WU. 1983. Ontogeny of the trilobite Dalmanitina (Dalmanitina) nanchengensis Lu. Palaeontologia Cathayana, 1: 123-153.    NEW
ROSS, R.J.J. 1951. Stratigraphy of the Garden City Formation in northeastern Utah, and its trilobite faunas. Bulletin of the Peabody Museum of Natural History, Yale University, 6: 1-161.
ROSS, R.J.J. 1951. The ontogenies of three Garden City (Early Ordovician) trilobites. Journal of Paleontology, 25(5): 578-586.
ROSS, R.J.J. 1953. Additional Garden City (Early Ordovician) trilobites. Journal of Paleontology, 27(5): 633-646.
SHAW, F.C. 1968. Early Middle Ordovician Chazy trilobites of New York. New York State Museum and Science Service Memoir, 17: 1-163.
SIMPSON, A.G., N.C., HUGHES, D.C., KOPASKA-MERKEL & R. LUDVIGSEN. 2005. Development of the caudal exoskeleton of the pliomerid trilobite Hintzeia plicamarginis new species. Evolution and Development, 7(6): 528-541.    Abstract
SNAJDR, M. 1990. Bohemian trilobites. Geological Survey. Prague. 265 p.
SPEYER, S.E. & B.D.E. CHATTERTON. 1989. Trilobite larvae and larval ecology. Historical Biology, 3: 27-60.
TEMPLE, J.T. 1952. The ontogeny of the trilobite Dalmanitina olini. Geological Magazine, 89: 251-262.
TRIPP, R.P., D.M., RUDKIN, & W. R. EVITT. 1997. Silicified trilobites of the genus Sphaerocoryphe from the Middle Ordovician of Virginia. Canadian Journal of Earth Sciences, 34: 770-788.
WHITTINGTON, H.B. 1941. Silicified Trenton trilobites. Journal of Paleontology, 15: 492-522.
WHITTINGTON, H.B. 1956. Beecher's supposed odontopleurid protaspis is a phacopid. Journal of Paleontology, 30: 104-109.
WHITTINGTON, H.B. 1959. Ontogeny of Trilobita, p. 127-144. In R. C. Moore (ed.). Treatise on Invertebrate Paleontology, Part O, Arthropoda 1. Geological Society of America & the University of Kansas Press, New York & Lawrence, Kansas, 560 p.
WHITTINGTON, H.B. 1960. Unique fossils from Virginia. Virginia Minerals, 6(3): 1-8.   NEW
WHITTINGTON, H.B. & S.W. CAMPBELL. 1967. Silicified Silurian trilobites from Maine. Bulletin of the Museum of Comparative Zoology at Harvard College, 135(9): 447-483.
WHITTINGTON, H.B. & W. R. EVITT. 1954. Silicified Middle Ordovician trilobites. Geological Society of America, Memoir, 59: 1-137.
ZHU, X.-J. & S.-C. PENG. 2004. Ontogeny of Cambrian trilobite Cheiruroides primigenius. Acta Palaeontologica Sinica, 43: 53-62.