Skip to main content Accessibility help
×
Home

Three new proetide trilobite larvae from the Lower Ordovician Garden City Formation in southern Idaho

  • Dong-Chan Lee (a1) and Brian D. E. Chatterton (a1)

Abstract

Larvae of three proetide trilobites are described from the Garden City Formation: Proetide A, Goniophrys prima, and Licnocephala cavigladius. The larvae of Proetide A share a spindle-shaped axis and natant hypostomal condition with other proetide larvae as synapomorphies. The forward-tapering glabella and slender posterior fixigenal area of post-larval cranidia of Proetide A indicate a close affinity to the earliest proetide family (Hystricuridae). The primitive nature of the larvae of Proetide A is further supported by the possession of plesiomorphic features, including four glabellar lobes and bilobed axial lobes (L1/L2/L3). Larval features of Goniophrys prima (a telephinid) such as an elliptical outline and smooth exoskeleton are not consistent with the hypothesis that the genus is the ancestor to younger telephinids. The larvae of Licnocephala cavigladius are typical of the Bathyuridae in having a smooth, ovoid shield and less distinct axial furrows.

Copyright

References

Hide All
Chatterton, B. D. E. 1980. Ontogenetic studies of Middle Ordovician trilobites from the Esbataottine Formation, Mackenzie Mountains, Canada. Palaeontographica Abteilung A, 171:174.
Chatterton, B. D. E. 1994. Ordovician proetide trilobite Dimeropyge, with a new species from northwestern Canada. Journal of Paleontology, 68:541556.
Chatterton, B. D. E., and Speyer, S. E.In press. Ontogeny of the Trilobita. In Whittington, H. B. (ed.), Treatise on Invertebrate Paleontology, Part O, Arthropod 1 (2nd edition). Geological Society of America and University of Kansas Press.
Edgecombe, G. D., Speyer, S. E., and Chatterton, B. D. E. 1988. Protaspid larvae and phylogenetics of encrinurid trilobites. Journal of Paleontology, 62:779799.
Fortey, R. A. 1975. The Ordovician trilobites of Spitsbergen. II. Asaphidae, Nileidae, Raphiophoridae and Telephinidae of the Valhallfonna Formation. Skrifter Norsk Polarinstitutt 162, 125 p.
Fortey, R. A. 1979. Lower Ordovician trilobites from the Catoche Formation (St. George Group), western Newfoundland. Bulletin of the Geological Survey of Canada, 321:61114.
Fortey, R. A. 1990. Ontogeny, hypostome attachment and trilobite classification. Palaeontology, 33:529576.
Fortey, R. A., and Chatterton, B. D. E. 1988. Classification of the trilobite suborder Asaphina. Palaeontology, 31:165222.
Fortey, R. A., and Owens, R. M. 1975. Proetida - a new order of trilobites. Fossils and Strata, 4:227239.
Hintze, L. F. 1953. Lower Ordovician trilobites from western Utah and eastern Nevada. Utah Geological and Mineralogical Survey Bulletin 48, 249 p.
Hintze, L. F. 1973. Lower and Middle Ordovician stratigraphic sections in the Ibex Area, Millyard County, Utah. Brigham Young University Geology Studies, 20:336.
Hu, C.-H. 1971. Ontogeny and sexual dimorphism of Lower Paleozoic Trilobita. Palaeontographica Americana, 7:31155.
Hupé, P. 1953. Classe des trilobites, p. 44246. In Piveteau, J. (ed.), Traités de Paléontologie. Masson Et Cie.
Marek, L. 1952. Contribution to the stratigraphy and fauna of the uppermost part of the Králů v Dvů r Shales (Ashgillian). Sborník U středního Ú stavu Geologickeho, 19:429455.
McNamara, K. J. 1986. A guide to the nomenclature of heterochrony. Journal of Paleontology, 60:413.
Raymond, P. E. 1913. A revision of the species which have been referred to the genus Bathyurus. Bulletin of Victoria Memorial Museum, 1:5169.
Ross, R. J. Jr. 1951a. Ontogenies of three Garden City (Early Ordovician) trilobites. Journal of Paleontology, 25:578586.
Ross, R. J. Jr. 1951b. Stratigraphy of the Garden City Formation in northwestern Utah, and its trilobite faunas. Bulletin of Peabody Museum of Natural History, Yale University 6, 161 p.
Ross, R. J. Jr. 1953. Additional Garden City (Early Ordovician) trilobites. Journal of Paleontology, 27:633646.
Speyer, S. E., and Chatterton, B. D. E. 1989. Trilobite larvae and larval ecology. Historical Biology, 3:2760.
Walcott, C. D. 1886. Second contribution to the studies on the Cambrian Faunas of North America. Bulletin of the United States Geological Survey, 30:369 p.
Whittington, H. B. 1958. Ontogeny of the trilobite Peltura scarabaeoides from Upper Cambrian, Denmark. Paleontology, 1:200206.
Whittington, H. B. 1988. Hypostomes of post-Cambrian trilobites. Memoirs of the New Mexico Bureau of Mines and Mineral Resources, 44:321339.
Whitworth, P. H. 1970. Ontogeny of the Upper Cambrian trilobite Leptoplastus crassicornis (Westergaard) from Sweden. Palaeontology, 13:100111.

Three new proetide trilobite larvae from the Lower Ordovician Garden City Formation in southern Idaho

  • Dong-Chan Lee (a1) and Brian D. E. Chatterton (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed