Hostname: page-component-745bb68f8f-hvd4g Total loading time: 0 Render date: 2025-01-25T22:39:27.103Z Has data issue: false hasContentIssue false
  • English
  • Français

New information on the coaptative devices in the Ordovician trilobites Placoparia and Crozonaspis, and its significance for their classification and phylogeny

Published online by Cambridge University Press:  03 November 2011

J.-L. Henry
J.-L. Henry
Affiliation:
Laboratoire de Paléontologie et de Stratigraphie, Université de Rennes I, Campus de Beaulieu, 35042 Rennes cedex, France. (Centre National de la Recherche Scientifique, G.R.E.C.O. 130007 ct A. T. P. ‘Evolution’, projet E7).
Get access Rights & Permissions [Opens in a new window]

Abstract

Many Ordovician trilobites possess morphological structures on the cephalon, the pygidium and sometimes also on the thoracic segments, which interlock during enrolment. These coaptative devices, also known in living arthropods, are functional, inherited, and seem to remain stable at the species level. Significant evolutionary changes in coaptative devices occur throughout time within the genera Placoparia (Pliomeridae) and Crozonaspis (Dalmanitidae). New data are presented which have relevance for the details of the coaptative structures in Placoparia (Coplacoparia), and for the classification of the dalmanitid species morenensis and dujardini. In some species of Crozonaspis and in Placoparia (Coplacoparia), interlocking structures prevent the possibility of shearing between cephalon and post-cephalic exoskeleton.

Keywords

Armorican Massifenrolmentevolutionfunctional morphologyIberian PeninsulaOrdovicianCheirurinaPhacopina.
Type
Structure and function
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 76 , Issue 2-3: Fossil Anthropods as Living Animals , 1985 , pp. 319 - 324
Copyright
Copyright © Royal Society of Edinburgh 1985

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Babin, Cl. & Racheboeuf, P. R. 1983. Les faunes du Paléozoïque et la reconstitution phylogénétique: jeux et enjeux. In Modalités, rythmes, mécanismes de l'évolution biologique. COLL INTERN CNRS 330, 57–65.Google Scholar
Bergström, J. 1973. Organization, life, and systematics of trilobites. FOSSILS STRATA 2, 1–69.CrossRefGoogle Scholar
Clarkson, E. N. K. & Henry, J.-L. 1973. Structures coaptatives et enroulement chez quelques trilobites ordoviciens et siluriens. LETHAIA 6, 105–32.CrossRefGoogle Scholar
Cuénot, L. 1919. La coaptation des fémurs antérieurs et de la tête chez les Phasmes. C R ACAD SCI 169, 835–8.Google Scholar
Fortey, R. A. & Owens, R. M. 1979. Enrolment in the classification of trilobites. LETHAIA 12, 219–26.Google Scholar
Hammann, W. 1971. Die Placopariinae (Trilobita, Cheirurina; Ordovizium). SENCKENBERGIANA LETHAEA 52, 53–75.Google Scholar
Hammann, W. 1983. Calymenacea (Trilobita) aus dem Ordovizium von Spanien; ihre Biostratigraphie, Ökologie und Systematik. ABH SENCKENB NATURFORSCH GES 542, 1–177.Google Scholar
Harland, W. B., Cox, A. V., Llewellyn, P. G., Pickton, C. A. G., Smith, A. G. & Walters, R. 1982. A geologic time scale. Cambridge: University Press.Google Scholar
Henry, J.-L. 1968. Crozonaspis struvei n.g. n.sp., Zeliszkellinae (Trilobita) de l'Ordovicien moyen de Bretagne. SENCKENBERGIANA LETHAEA 49, 367–81.Google Scholar
Henry, J.-L. 1980. Trilobites ordoviciens du Massif Armoricain. MEM SOC GEOL MINERAL BRETAGNE 22, 1–250.Google Scholar
Henry, J.-L. & Clarkson, E. N. K. 1975. Enrolment and coaptations in some species of the Ordovician trilobite genus Placoparia. FOSSILS STRATA 4, 87–95.CrossRefGoogle Scholar
Hintze, L. F. 1952. Lower Ordovician trilobites from Western Utah and Eastern Nevada. UTAH GEOL MINERAL SURV 48, 1–249.Google Scholar
Paris, Fl. 1979. Les Chitinozoaires de la Formation de Louredo, Ordovicien Supérieur du synclinal de Buçaco (Portugal). PALAEONTOGRAPHICA A 164, 24–51.Google Scholar
Romano, M. 1976. The trilobite genus Placoparia from the Ordovician of the Valongo area, North Portugal. GEOL MAG 113, 11–28.Google Scholar
Ross, R. J. 1970. Ordovician Brachiopods, Trilobites, and Stratigraphy in Eastern and Central Nevada. GEOL SURV PROF PAP 639, i–iv, 1–103.Google Scholar
Rostand, J. & Tétry, A. 1962. La Vie. Paris: Larousse.Google Scholar
Sahuc, L. J. M. 1969. Coaptations chez le grillon domestique. BULL BIOL FR BELG 103, 9–130.Google Scholar
Tétry, A. 1969. Outils animaux et végétaux. SCIENCE PROGRES DECOUVERTE 3416, 481–90. Paris: Dunod.Google Scholar