Hostname: page-component-848d4c4894-4hhp2 Total loading time: 0 Render date: 2024-06-06T18:21:01.147Z Has data issue: false hasContentIssue false
  • English
  • Français

Saharatheca lobata n. gen. and sp.: a new medullosan (seed fern) pollen organ from the Middle Pennsylvanian of Illinois

Published online by Cambridge University Press:  14 July 2015

Benton M. Stidd
Benton M. Stidd*
Affiliation:
Department of Biological Sciences, Western Illinois University, Macomb 61455
Get access Rights & Permissions [Opens in a new window]

Abstract

Several specimens of a pollen organ containing Monoletes pollen occur in a single coal ball collected from the Herrin No. 6 Coal at the Sahara Coal Company Mine in southern Illinois. Specimens are 3–4 cm long, up to 1 cm wide, and are either bilobed or trilobed; 5–7 pollen sacs are arranged along each side of a discontinuously sclerified ground tissue plate extending into each lobe. The vascular supply from the peduncle breaks up by repeated dichotomies and one bundle descends along the outer side of each pollen sac. The mode of dehiscence and the structure of the tip of the organ remain unknown. Each lobe (and contained sporangia) is hypothesized to be derived from an ancestral fertile frond segment bearing pendulous sporangia.

Type
Research Article
Information
Journal of Paleontology , Volume 65 , Issue 1 , January 1991 , pp. 160 - 166
Copyright
Copyright © The Journal of Paleontology 

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

Dennis, R. L., and Eggert, D. A. 1978. Parasporotheca, gen. nov., and its bearing on the interpretation of the morphology of permineralized medullosan pollen organs. Botanical Gazette, 139:117–139.Google Scholar
Dufek, D., and Stidd, B. M. 1981. The vascular system of Dolerotheca and its phylogenetic significance. American Journal of Botany, 68:897–907.Google Scholar
Eggert, D. A., and Rothwell, G. W. 1979. Stewartiotheca gen. n. and the nature and origin of complex permineralized medullosan pollen organs. American Journal of Botany, 66:851–866.Google Scholar
Goeppert, H. R., and Stenzel, G. 1881. Die Medulloseae: eine neue gruppe der fossilen Cycadeen. Palaeontogaphica N.F. VIII(XXVIII):113–127.Google Scholar
Oliver, F. W., and Scott, D. H. 1904. On the structure of the Paleozoic seed Lagenostoma lomaxi, with a statement of the evidence upon which it is referred to Lyginodendron . Philosophical Transactions of the Royal Society of London, B197:193–247.Google Scholar
Phillips, T. L., Avcin, M. J., and Berggren, D. 1976. Fossil peat from the Illinois Basin: a guide to the study of coal balls of Pennsylvanian age. Educational Series 11, Illinois State Geological Survey, Urbana, 39 p.Google Scholar
Rothwell, G. W., and Eggert, D. A. 1986. A monograph of Dolerotheca Halle, and related complex permineralized medullosan pollen organs. Transactions of the Royal Society of Edinburgh, Earth Sciences, 77:47–49.Google Scholar
Stidd, B. M. 1990. Further documentation of the structure of Dolerotheca and a critique of other theories. Palaeontographica, B217:51–86.Google Scholar
Stidd, B. M., Leisman, G. A., and Phillips, T. L. 1977. Sullitheca dactylifera gen. et sp. n.: a new medullosan pollen organ and its evolutionary significance. American Journal of Botany, 64:994–1002.Google Scholar