orderasaphida

LARVAE & TRILOBITE ORDERS:
ASAPHIDA

From Chatterton et al., 1994

CLASSIFICATION & LARVAE:

The current knowledge on larval morphologies within the Asaphida is not so bad, even if the larvae of only one third of the families composing the order have been described so far. Indeed, at the superfamilial level, the larval morphology of only one taxon (i.e., Dikelokephaloidea) is still unknown.
While larvae of the most primitive Asaphida (i.e. the Anomocaroidea) greatly resemble those of Ptychoparida, protaspides of the other members of the group possess a unique morphology, typical of a planktonic mode of life.

Table 1. Classification scheme of the order Asaphida (from Fortey, new Treatise, 1997, slightly modified). Protaspid larvae of 11 (yellow & bold) of the 32 families have been described so far.

LOCALITIES:

1. Montagne Noire, France. LOWER ORDOVICIAN
2. Valhallfonna Formation, Spitsbergen. LOWER ORDOVICIAN
3. Esbataottine Formation, Mackenzie Mts., Northwest Territories, Canada. MIDDLE ORDOVICIAN.
4. Whittaker Formation, Mackenzie Mts., Northwest Territories, Canada. UPPER ORDOVICIAN
5. Table Head Formation, Newfoundland & Labrador, Canada. MIDDLE ORDOVICIAN
6. Edinburg Formation, Virginia, USA. MIDDLE ORDOVICIAN.
7. Martinsburg Formation, Virginia, USA. MIDDLE ORDOVICIAN.
8. Oranda Formation, Virginia, USA. UPPER ORDOVICIAN
9. Lincolnshire Formation, Virginia, USA. MIDDLE ORDOVICIAN.
10. Beechers Trilobite Beds, New York, USA. MIDDLE ORDOVICIAN.
11. Crown Point Formation, New York, USA. MIDDLE ORDOVICIAN.
12. Chazy group, New York, USA. EARLY/MIDDLE ORDOVICIAN.
13. Bonneterre Dolomite, Missouri, USA. UPPER CAMBRIAN
14. Deadwood Formation, South Dakota, USA. UPPER CAMBRIAN
15. Flathead Formation, Big Horn Mts, Wyoming, USA. UPPER CAMBRIAN
16. Garden City Formation, Idaho, USA. EARLY ORDOVICIAN
17. Dunderberg Formation, Nevada, USA. UPPER CAMBRIAN
18. Fillmore Limestone, Utah, USA. LOWER ORDOVICIAN
19. Tangtou Formation, Jiangsu Province, CHINA. UPPER ORDOVICIAN
20. "mittelkambrischen Geschriebe", Germany. MIDDLE CAMBRIAN

ARTICLES:

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

BERARD, P., E.N.K. CLARKSON, & C.M. TAYLOR. 2000. The ontogeny of Taihungshania miqueli (Bergeron, 1893) from the Arenig of the Montagne Noire, southern France. Transactions of the Royal Society of Edinburgh, 90: 147-163.
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., G.D., EDGECOMBE, S.E., SPEYER, A.S., HUNT, & R.A. FORTEY. 1994. Ontogeny and relationships of Trinucleoidea (Trilobita). Journal of Paleontology, 68(3): 523-540.
DEMETER, E.J. 1973. Lower Ordovician pliomerid trilobites from western Utah. Brigham Young University Geology Studies, 20: 37-65.
EVITT, W.R. 1961. Early ontogeny in the trilobite family Asaphidae. Journal of Paleontology, 35(5): 986-995.    Abstract
FORTEY, R.A. & B.D.E. CHATTERTON. 1988. Classification of the trilobite suborder Asaphina. Palaeontology, 31(1): 165-222.    pdf version
HU, C.-H. 1969. Ontogeny and sexual dimorphism of three Upper Cambrian trilobites. Journal of Nanyang University, 3: 438-462.
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. 1975. Ontogenies of two species of silicified trilobites from the Middle Ordovician of Virginia. Transactions and Proceedings of the Palaeontological Society of Japan (new series), 97: 32-47.
HU, C.-H. 1981. Studies on the ontogenetic and phylogenetic development of two Upper Cambrian trilobites from South Dakota. Transactions and Proceedings of the Palaeontological Society of Japan (new series), 123: 159-167.
HU, C.-H. 1983. Ontogenetic and phylogenetic development of two Upper Cambrian trilobites from the Nolichuky Formation, Tennessee. Transactions and Proceedings of the Palaeontological Society of Japan (new series), 129: 26-34.
HU, C.-H. 1986. Ontogenetic development of Cambrian trilobites from British Columbia and Alberta, Canada (Part II). Journal of Taiwan Museum, 39(1): 1-44.
HU, C.-H. & L.L., TAN. 1971. Ontogenies of two Upper Cambrian trilobites from northern Black Hills, South Dakota. Transactions and proceedings of the Palaeontological Society of Japan (new series), 82: 61-72.
PALMER, A.R. 1962. Comparative ontogeny of some opisthoparian, gonatoparian and proparian Upper Cambrian Trilobites. Journal of Paleontology, 36(1): 87-96.    Abstract
PENG, S.-C. 1994. Ontogeny of Dichelepyge lata Peng (Trilobita, Tremadocian) from Luxi, western Hunan. Acta Palaeontologica Sinica, 33(1): 48-62.
ROSS, R.J.J. 1951. The ontogenies of three Garden City (Early Ordovician) trilobites. Journal of Paleontology, 25(5): 578-586.
RUDOLPH, F. 1994. Die Trilobiten der mittelkambrischen Geschriebe. Verlag Frank Rudolph, Wakendorf. 309 pp.    NEW
RUDOLPH, F. & R. SCHALLREUTER. 1998. Identifizierung von Agnostus calkeri Kruizinga 1918 als larvales Asaphiden-Hypostom (Trilobita). Palaeontologische Zeitschrift, 72(3/4): 307-310
SHAW, F.C. 1968. Early Middle Ordovician Chazy trilobites of New York. New York State Museum and Science Service Memoir, 17: 1-163.
SPEYER, S.E. & B.D.E. CHATTERTON. 1989. Trilobite larvae and larval ecology. Historical Biology, 3: 27-60.
TRIPP, R.P. & W.R. EVITT. 1986. Silicified trilobites of the family Asaphidae from the Middle Ordovician of Virginia. Palaeontology, 29: 705-724.    pdf version
TRIPP, R.P., Z. ZHOU & Z. PAN. 1989. Trilobites from the Upper Ordovician Tangtou Formation, Jiangsu Province, China. Transactions of the Royal Society of Edinburgh, 80: 25-68.
VACCARI, N. E., B.G., WAISFELD, B.D.E., CHATTERTON & G.D., EDGECOMBE. 2006. New raphiophorid trilobites from the Ordovician of Argentina and their biogeographic implications. AAP, Memoir, 32: 353-374.
WHITTINGTON, H.B. 1959. Silicified Middle Ordovician trilobites: Remopleurididae, Trinucleidae, Raphiophoridae, Endymioniidae. Bulletin of the Museum of Comparative Zoology at Harvard College, 121(8): 371-496.
WHITTINGTON, H.B. 1965. Trilobites of the Ordovician Table Head Formation, western Newfoundland. Bulletin of the Museum of Comparative Zoology at Harvard College, 132(4): 275-442.