Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-30T21:06:03.820Z Has data issue: false hasContentIssue false
  • English
  • Français

10.—Triradioxylon—a New Genus of Lower Carboniferous Petrified Stems and Petioles together with a Review of the Classification of Early Pterophytina

Published online by Cambridge University Press:  06 July 2012

P. D. W. Barnard  and
A. G. Long
P. D. W. Barnard
Affiliation:
Department of Botany, University of Reading
A. G. Long
Affiliation:
Hancock Museum, Newcastle upon Tyne.
Get access Rights & Permissions [Opens in a new window]

Synopsis

Triradioxylon gen. nov. is erected for petrified stems and petioles in which the primary xylem has a triradiate form and possesses protoxylem at the ends of the arms and in the central region. Secondary xylem is dense and composed of small tracheids having multiseriate bordered pits on all walls. Rays are narrow and high. The cortex has sclerotic nests and radial bands of fibres (sparganum structure).

In the type species T. primaevum sp. nov. the petioles are borne 5–6 cm apart in a phyllotactic spiral of ⅓ on a stem about 1 cm (or more) diameter. The petiole is swollen at its base (about 8 mm diameter) and very gradually tapers to about 2 mm in the rachis which has not been seen to dichotomise. The length of petiole up to the first pinna may exceed 10 cm. Pinnae arose alternately and themselves branched. The T-shaped petiolar bundle has two protoxylem groups at the end of each arm and the central protoxylem divided into three in the rachis.

Two detached rachises which cannot be assigned with certainty to Triradioxylon primaevum are placed in the genus Lyginorachis and named L. whitadderensis sp. nov. In these the T-shaped vascular bundle is slightly larger than that in the rachises of T. primaevum and the ends of the transverse arms are wider and may possess three protoxylem groups.

The rachises in both T.primaevum and L. whitadderensis bear alternate triarch pinna-traces but in L. whitadderensis a pair of sub-opposite monarch pinna-traces is also present.

Triradioxylon is classified along with Buteoxylon in the family Buteoxylonaceae placed tentatively as incertae sedis in the Pteridosperms although showing some affinity with Aneurophyton in the Progymnospermopsida.

Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 69 , Issue 10 , 1975 , pp. 231 - 249
Copyright
Copyright © Royal Society of Edinburgh 1975

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

References to Literature

Andrews, H. N., 1961. Studies in Paleobotany, p. 68. New York: Wiley.Google Scholar
Andrews, H. N., 1970. Traité de Paléobotanique, IV, pp. 14 and 25. (Ed. Boureau, E..) Paris: Masson.Google Scholar
Andrews, H. N. and Phillips, T. L., 1968. Rhacophyton from the Upper Devonian of West Virginia. J. Linn. Soc. (Bot.), 61, 37–64.Google Scholar
Arnold, C. A., 1940. Structure and relationships of some Middle Devonian plants from western New York. Am. J. Bot., 27, 57–63.CrossRefGoogle Scholar
Banks, H. P., 1968. The early history of land plants. Ch. 2, 73–107. In Drake, T. E. (Ed.), Evolution and Environment. Yale Univ. Press.Google Scholar
Barnard, P. D. W., 1960. Studies on some Lower Carboniferous plants from East Lothian. Ph.D. Thesis, Univ. Lond.Google Scholar
Barnard, P. D. W. and Long, A. G., 1973. On the structure of a petrified stem and some associated seeds from the Lower Carboniferous Rocks of East Lothian, Scotland. Trans. Roy. Soc. Edinb., 69, 91–108.Google Scholar
Beck, C. B., 1957. Tetraxylopteris schmidtii gen. et sp. nov., a probable pteridosperm precursor from the Devonian of New York. Am. J. Bot., 44, 350–367.CrossRefGoogle Scholar
Beck, C. B., 1960. Studies on New Albany Shale Plants. I. Stenokoleos simplex comb. nov. Am. J. Bot., 47, 115–124.Google Scholar
Bonamo, P. M. and Banks, H. P., 1967. Tetraxylopteris schmidtii: its fertile parts and its relationship within the Aneurophytales. Am. J. Bot., 54, 755–768.Google Scholar
Corsin, P., 1960. Classification des Ptéridophytes et des Ptéridospermophytes du Carbonifère. Bull. Soc. Géol. Fr., 2, 566–572.Google Scholar
Galtier, J., 1970. Recherches sur les végétaux à structure conservée du Carbonifère inférieur français. Paléobiologie Continentale, 1, 170–181.Google Scholar
Hoskins, J. H. and Cross, A. T., 1951. The structure and classification of four plants from the New Albany Shale. Am. Midl. Nat., 46, 684–716.Google Scholar
Kidston, R. and Lang, W. H., 1923. On Palaeopitys Milleri, M'Nab. Trans. Roy. Soc. Edinb., 53, 409–417.Google Scholar
Kräusel, R. and Weyland, H., 1923. Beitrage zu Kenntnis der Devonflora. Senckenbergiana, 5, 154–184.Google Scholar
Kräusel, R. and Weyland, H., 1929. Beitrage zu Kenntnis der Devonflora. Abh. Senckenb. Naturforsch. Ges., 41, 317–359.Google Scholar
Kräusel, R. and Weyland, H., 1938. Neue Pflanzenfunde im Mitteldevon von Elberfeld. Palaeontographica, 83B, 172–195.Google Scholar
Leclercq, S., 1951. Étude morphologique et anatomique d'une fougère du Devonien Supérieur, le Rhachophyton zygopteroides nov. sp. Annls Soc. Géol. Belg. (Mem.), 9, 1–62.Google Scholar
Leclercq, S. and Bonamo, P. M., 1971. A study of the fructification of Milleria (Protopteridium) thomsonii Lang from the Middle Devonian of Belgium. Palaeontographica, 136B, 83–114.Google Scholar
Leclercq, S. and Bonamo, P. M., 1973. Rellimia thomsonii, a new name for Milleria (Protopteridium) thomsonii Lang 1926 emend. Leclercq and Bonamo 1971. Taxon, 22, 435–437.Google Scholar
Long, A. G., 1963. Some specimens of Lyginorachis papilio Kidston associated with stems ofPitys. Trans. Roy. Soc. Edinb., 65, 211–224.Google Scholar
Long, A. G., 1964. Some Specimens of Stenomyelon and Kalymma from the Calciferous Sandstone Series of Berwickshire. Trans. Roy. Soc. Edinb., 65, 435–447.Google Scholar
Long, A. G., 1967. Some specimens of Protoclepsydropsis and Clepsydropsis from the Calciferous Sandstone Series of Berwickshire. Trans. Roy. Soc. Edinb., 67, 95–106.Google Scholar
Matten, L. C., 1968. Actinoxylon banksii gen. et sp. nov.: a progymnosperm from the Middle Devonian of New York. Am. J. Bot., 55, 773–782.Google Scholar
Matten, L. C. and Banks, H. P., 1966. Triloboxylon ashlandicum gen. and sp. n. from the Upper Devonian of New York. Am. J. Bot., 53, 1020–1028.Google Scholar
Matten, L. C. and Banks, H. P., 1967. Relationship between the Devonian progymnosperm genera Sphenoxylon and Tetraxylopteris. Bull. Torr. Bot. Club, 94, 321–333.Google Scholar
Matten, L. C. and Banks, H. P., 1969. Stenokoleos bifidus sp. n. in the Upper Devonian of New York State. Am. J. Bot., 56, 880–891.Google Scholar
Read, C. B. and Campbell, G., 1939. Preliminary account of the New Albany shale flora. Am. Midl. Nat., 21, 435–453.Google Scholar
Scheckler, S. E. and Banks, H. P., 1971 a. Anatomy and relationships of some Devonian progymnosperms from New York. Am. J. Bot., 58, 737–751.Google Scholar
Scheckler, S. E. and Banks, H. P., 1971 b. Proteokalon a new genus of progymnosperms from the Devonian of New York State and its bearing on phylogenetic trends in the group. Am. J. Bot., 58, 874–884.Google Scholar
Walton, J., 1926. Contributions to the knowledge of Lower Carboniferous Plants, I & II. Phil. Trans. Roy. Soc. B., 215, 201–204.Google Scholar
Walton, J., 1931. Contributions to the knowledge of Lower Carboniferous Plants, III. Phil. Trans. Roy. Soc. B., 219, 347–379.Google Scholar
Walton, J., 1957. On Protopitys (Göppert); with a description of a fertile specimen Protopitys scotica sp. nov. from the Calciferous Sandstone Series of Dunbartonshire. Trans. Roy. Soc. Edinb., 63, 333–339.CrossRefGoogle Scholar