Hostname: page-component-848d4c4894-x5gtn Total loading time: 0 Render date: 2024-06-02T12:25:22.168Z Has data issue: false hasContentIssue false

Melanosclerites: first North American report of these problematic microfossils and discussion of their affinity

Published online by Cambridge University Press:  20 May 2016

P. B. Cashman*
Affiliation:
Department of Geology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 0W0

Abstract

Melanosclerites are rod-shaped, pseudochitinous microfossils of problematic affinity. They have not been widely studied. The first North American discovery of melanosclerites is here reported; Melanostylus coronifer and Melanosteus acutus (the latter with two subspecies), of Devonian (Late Siegenian) age, were discovered in the Indian Cove Formation of the Upper Gaspé Limestones from the Gaspé Peninsula, Quebec, Canada.

These melanosclerites bear a strong resemblance to the modern cubomedusa polyp Carybdea alata and the planula stages of the hydrozoan Pennaria tiarella. They are interpreted as being the embryonic planula and early polyp stages of scyphozoans, cubozoans, and hydrozoans.

Consequently, Semenola semen Schallreuter, 1981, is considered an early growth stage of M. acutus anceps and thus a junior synonym; similarly, Eichbaumia incus is a junior synonym of Melanostylus coronifer; while, on the basis of their three-fold symmetry, Orthopelta? femuralis Eller, 1945, and Menola os Schallreuter, 1981, are treated as junior synonyms of Melanofurca neptuni Eisenack, 1963. Melanosclerites could represent the planula and polyp stages of any of the three classes of Cnidaria; therefore, the order Melanoscleritoitidea Eisenack, 1963, and the family Melanoscleritoitidae are here rejected because the supposed family crosses the boundaries of classes. The new subspecific combinations Melanosteus acutus acutus, M. acutus filiformis, and M. acutus anceps are proposed, their diagnoses being emended; the diagnosis of Melanostylus coronifer is also emended.

Melanosclerites appear to be strongly facies controlled and thus may have potential for paleoenvironmental and paleogeographical reconstructions.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

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

Arneson, A. C., and Cutress, C. E. 1976. Life history of Carybdea alata Renaud, 1830 (Cubomedusae), p. 227236. In Mackie, G. O. (ed.), Coelenterate Ecology and Behavior. Plenum Press, New York and London.Google Scholar
Calder, D. R. 1988. Shallow-water hydroids of Bermuda. The Athecatae. Life Sciences Contributions, No. 148, Royal Ontario Museum, University of Toronto Press, Toronto, 107 p.Google Scholar
Dunn, D. F., and Liberman, M. H. 1983. Chitin in sea anemone shells. Science, 221:157159.CrossRefGoogle ScholarPubMed
Eisenack, A. 1932. Neue mikrofossilien des baltischen Silurs. II. Paläontologische Zeitschrift, 14:257277.Google Scholar
Eisenack, A. 1934. Neue mikrofossilien des baltischen Silurs III und neue mikrofossilien des bohemischen Silurs I. Paläontologische Zeitschrift, 16:5276.Google Scholar
Eisenack, A. 1942. Die Melanoskleritoiden, ein neue Gruppe silurischer mikrofossilien aus dem unterstamm der nesseltiere. Paläontologische Zeitschrift, 23:157180.Google Scholar
Eisenack, A. 1963. Melanoskeriten aus anstehenden Sedimenten und aus Geschieben. Paläontologische Zeitschrift, 37:122134.CrossRefGoogle Scholar
Eisenack, A. 1971. Die mikrofauna der Ostseekalk (Ordovizium). 3. Graptolithen, melanoskleriten, spongien, radiolarien, problematika nebst 2 nachtragen uber foraminiferen und phytoplankton. Neues Jarbuch fur Geologie und Paläontologie, 137:337357.Google Scholar
Eller, E. R. 1945. Article XII. Scolecodonts from the Trenton Series (Ordovician) of Ontario, Quebec, and New York. Annals of the Carnegie Museum, 30:119212.Google Scholar
Górka, H. 1971. Sur les Melanosklerites extraits des Galets erratiques Ordovician de Pologne. Société Geologique et Minérologique de Bretagne, Bulletin Serie C, 3(1):2940.Google Scholar
Hotchkiss, A. E., Martin, V. J., and Apkarian, R. P. 1984. A scanning electron microscope surface and cryofracture study of development in the planulae of the hydrozoan, Pennaria tiarella. Scanning Electron Microscopy, 2:717727.Google Scholar
Hurst, J., and Surlyk, F. 1983. Depositional environments along a carbonate ramp to slope transition in the Silurian of Washington Land, North Greenland. Canadian Journal of Earth Sciences, 20:473499.Google Scholar
Laufeld, S. 1979. Melanosclerites, p. 7980. In Jaanusson, V., Laufeld, S., and Skoglund, R. (eds.), Lower Wenlockian Faunal and Floral Dynamics—Vattenfallet section, Gotland. Sveriges Geologiska Undersökning, Arsbok 73(3), Series C, 762, Uppsala.Google Scholar
Livermore, R. A., Smith, A. G., and Briden, J. C. 1985. Paleomagnetic constraints on the distribution of continents in the Late Silurian and Early Devonian. Philosophical Transactions of the Royal Society of London, Series B, 309(1138):2956.Google Scholar
Martin, V., and Archer, W. E. 1986. A scanning electron microscopic study of embryonic development of a marine hydrozoan. Biologic Bulletin, 171:116125.Google Scholar
Martin, V., Chia, F., and Koss, R. 1983. A fine structural study of metamorphosis of the hydrozoan Mitrocomella polydiademata. Journal of Morphology, 176:261287.CrossRefGoogle ScholarPubMed
Nolvak, J. 1980. Chitinozoans in biostratigraphy of the northern east Baltic Ashgillian. A preliminary report. Acta Palaeontologica Polonica, 20:253260.Google Scholar
Pichler, R. 1971. Mikrofossilien aus dem Devon der sudlichen Eifeler Kalkmulden. Senkenbergiana Lethaea, 52:315357.Google Scholar
Robins, M. W. 1972. A new commensal hydroid from Antarctica. The British Antarctica Survey Bulletin, 28:7581.Google Scholar
Schallreuter, R. 1981. Microfossilien aus Geschieben. I. Melanoskleriten. Der Geschiebesammler, 15:107130.Google Scholar
Scotese, C. R. 1984. An introduction to this volume: Paleozoic paleomagnetism and the assembly of Pangea, p. 110. In van der Voo, R., Scotese, C. R., and Bonhommet, N. (eds.), Plate Reconstruction from Paleozoic Paleomagnetism. Geodynamics Series, 12, American Geophysical Union, Washington, D.C.Google Scholar
Scotese, C. R., van der Voo, R., and Barrett, S. F. 1985. Silurian and Devonian base maps. Philosophical Transactions of the Royal Society of London, Series B, 309(1138):5775.Google Scholar
Sheehan, P. M., and Lesperance, P. J. 1988. Faunal assemblages of the upper Gaspe Limestones, early Devonian of eastern Gaspé, Quebec. Canadian Journal of Earth Sciences, 25:14321449.Google Scholar
Taugourdeau, P. 1979. Incertae sedis et microfossiles divers conserves en matière organique du Paleozoique Saharien. Revue de Micropaléontologie, 21(3):149159.Google Scholar
Vervoot, W. 1966. Skeletal structure in the Solanderiidae and its bearing on hydroid classification, p. 373396. In Rees, W. J. (ed.), The Cnidaria and their Evolution. Symposia of the Zoological Society of London, No. 16, Academic Press Inc. (London) LTD, London, New York.Google Scholar