Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-26T04:22:54.579Z Has data issue: false hasContentIssue false
  • English
  • Français

The Relation of the Valves to the Pedicle in the Strophomenid Brachiopods

Published online by Cambridge University Press:  01 May 2009

Muriel A. Arber
Muriel A. Arber
Affiliation:
Sedgwick Museum, Cambridge
Get access Rights & Permissions [Opens in a new window]

Extract

The relation of the valves to the pedicle is among the fundamental characters on the basis of which the phylum Brachiopoda has been divided into five orders (see Thomson, 1927). In a previous paper (Arber, 1939), I pointed out that, on this classification, the order Protremata cannot be regarded as a homogeneous group, since in the orthids the pedicle apparently emerged through an open delthyrium, while in the strophomenid Leptaena it emerged through an entirely separate foramen situated in the ventral valve. Schuchert in 1913 (p. 383) defined the whole superfamily Strophomenacea as being characterized by a pedicle which, when present, was small, and emerged at the apex of the valve. A pedicle-foramen is, however, by no means of universal occurrence, and its existence has also been often overlooked in systematic descriptions, so that, in spite of Schuchert's definition, some doubt has nevertheless remained as to whether the form of pedicle-opening found in Leptaena and a few closely allied genera is genuinely typical of the whole of the strophomenids, thus creating a developmental distinction between that group and the orthids. I have therefore examined as many as possible of the available specimens and descriptions of the strophomenids, with the results here recorded.

Type
Articles
Information
Geological Magazine , Volume 77 , Issue 2 , April 1940 , pp. 161 - 174
Copyright
Copyright © Cambridge University Press 1940

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

LITERATURE CITED

Arber, M. A., 1939. The Nature and Significance of the Pedicle-foramen of Leptaena Dalman. Geol. Mag., Ixxvi, 82.CrossRefGoogle Scholar
Beecher, C. E., 1901. Studies in Evolution, Yale Bicentennial Publications, New York and London.Google Scholar
Davidson, T., 1871. A Monograph of the British Fossil Brachiopoda. Part VII. The Silurian Brachiopoda. No. 4. Mon. Palaeontogr. Soc., London.Google Scholar
Hall, J., and Clarke, J. M., 1892. An Introduction to the Study of the Genera of Palaeozoic Brachiopoda. Palaeont. New York, viii, pt. I.Google Scholar
Kozlowski, R., 1929. Les Brachiopodes gothlandiens de la Podolie Polonaise. Palaeont. Polonica, Warsaw, 1.Google Scholar
Lamont, A., 1934. Lower Palaeozoic Brachiopoda of the Girvan District: Suggestions on Morphology in relation to Environment. Ann. Mag. Mat. Hist., 10, xiv, 161.Google Scholar
Opik, A., 1930. Brachiopoda Protremata der estländischen ordovizischen Kukruse-Stufe. Acta Comm. Univ. Tartu., A xvii, 1.Google Scholar
Opik, A., 1932. Über die Plectellinen. Acta Comm. Univ. Tartu., A xxiii, 3.Google Scholar
Opik, A., 1933. Über Plectamboniten. Acta Comm. Univ. Tartu., A xxiv, 7.Google Scholar
Schuchert, C., 1913, revised by. Brachiopoda (pp. 355–420), in Text-book of Paleontology, edited by Eastman, C. R., adapted from German of von Zittel, K. A., ed. 2, vol. i, London.Google Scholar
Schuchert, C., and Cooper, G. A., 1932. Brachiopod Genera of the Suborders Orthoidea and Pentameroidea. Mem. Peabody Mus., Yale, iv pt. 1.Google Scholar
Schuchert, C., and LeVene, C. M., 1929. Brachiopoda.(Generum et Genotyporum Index et Bibliographia). Fossilium Catalogus, i, Pars 42, Berlin.Google Scholar
Shirley, J., 1938. The Fauna of the Baton River Beds (Devonian), New Zealand. Quart. Journ. Geol. Soc., xciv, 459.CrossRefGoogle Scholar
Thomson, J. A., 1927. Brachiopod Morphology and Genera (Recent and Tertiary). Man. N.Z. Bd. Sci. Art, 7.Google Scholar
Ulrich, E. O., and Cooper, G. A., 1936. New Silurian Brachiopods of the Family Triplesiidae. Journ. Paleont. 10, 331.Google Scholar
Ulrich, E. O., 1938. Ozarkian and Canadian Brachiopoda. Geol. Soc. America, Special Papers, No. 13.Google Scholar
De Verneuil, É., 1845, in Murohison, R. I., De Verneuil, É., and De Keyserling, A.. Géologie de la Russie d'Europe et des Montagnes de I'Oural. Vol. ii. Paléontologie, London and Paris.Google Scholar
Verneuil, É. De, 1848. Note sur quelques espèces de Leptaena à crochet perforé. Bull. Soc. géol. Fr., 2, v, 347.Google Scholar
Wilson, A. E., 1926. An Upper Ordovician Fauna from the Rocky Mountains, British Columbia. Geol. Surv. Canada, Bull. No. 44, Contributions to Canadian Palaeontology, 1.Google Scholar