World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0001885646
Reproduction Date:

Title: Bennettitales  
Author: World Heritage Encyclopedia
Language: English
Subject: 2015 in paleobotany, Anthophyta, Cycadeoidea, Williamsonia (plant), Gnetophyta
Collection: Bennettitales, Mesozoic Life, Prehistoric Plants
Publisher: World Heritage Encyclopedia


Temporal range: Triassic to Cretaceous
A Cycadeoid, showing an "inflorescence" in the top-right
Scientific classification
Kingdom: Plantae
Superdivision: Spermatophyta
Division: Cycadophyta
Subdivision: Cycadophyta
Class: Spermatopsida
Order: Bennettitales †

Bennettitales (the cycadeoids) is an extinct order of seed plants that first appeared in the Triassic period and became extinct in most areas toward the end of the Cretaceous (i.e. they existed around ),[1] although some Bennettitales appear to have survived into Oligocene times in Tasmania and eastern Australia.[2] Some were characterized by thick trunks and pinnately compound leaves that bore a superficial resemblance to those of cycads, differing primarily in stomatal arrangement.[3]

The taxon comprises two groups, the Cycadeoidaceae, represented by Cycadeoidea and Monanthesia which had stout trunks and bisporangiate strobili (cones serving as their reproductive structures), and the Williamsoniaceae including Williamsonia, Williamsoniella, Wielandella and Ischnophyton which had slender, branching trunks and either bisporangiate or monosporangiate strobili. Bennettitales have been placed among the anthophytes and for some time were considered to be close relatives of the flowering plants on account of their flower-like reproductive structures (a whorl of microsporangiate structures that surround an inner receptacle).[1] However, more detailed morphological studies have shown the hypothetical anthophytes clade to be polyphyletic, with the Bennettitales more closely related to the cycads, ginkgo and conifers than to the angiosperms.[4] Molecular fossil evidence, however, indicates the possibility that Bennettitales and Angiosperms (along with Gigantopteridales) form a clade, based on the presence of oleanane in fossils of these groups.[5]



  1. ^ a b Speer, Brian R., 2000. Introduction to the Bennettitales (accessed 13 Oct 2005).
  2. ^ McLoughlin, S., Carpenter, R.J. & Pott, C., 2011. Ptilophyllum muelleri (Ettingsh.) comb. nov. from the Oligocene of Australia: Last of the Bennettitales? International Journal of Plant Sciences 172, 574–585.
  3. ^ Pigg, Kathleen. 2005 The Cycads, Cycadeoids (Bennettitales) and Ginkgophytes (accessed 21 Sept 2007).
  4. ^ Crepet, W. L. (2000). """Progress in understanding angiosperm history, success, and relationships: Darwin's abominably "perplexing phenomenon. Proceedings of the National Academy of Sciences 97 (24): 12939–41.  
  5. ^ Taylor, D. W. and Hongqi Li and Dahl, Jeremy and Fago, F. J. and Zinneker, D. and Moldowan, J. M. (2006). "Biogeochemical evidence for the presence of the angiosperm molecular fossil oleanane in Paleozoic and Mesozoic non-angiospermous fossils". Paleobiology 32 (2): 179–90.  

External links

  • Gymnosperms
  • Lecture Notes on Mesozoic Mesophytic Communities
  • Weblinks to articles about the Bennettitales
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.