The bennettitalean trunk genera Cycadeoidea and Monanthesia in the Purbeck, Wealden and Lower Greensand of southern England: a reassessment

Watson, Joan; Lydon, Susannah J.

doi:10.1016/j.cretres.2003.10.003

Cited by 12 publications

(10 citation statements)

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“…Flowers in cycadeoids (e.g., Cycadeoidea Buckland ex Lindley and Hutton or Monanthesia Wieland ex Delevoryas) are always bisexual, positioned in branch axils, and deeply sunken among the mantle of persistent leaf bases, and they are interpreted to have never fully opened (Delevoryas 1968;Crepet 1974;Watson and Sincock 1992;Watson and Lydon 2004).…”

Section: Introductionmentioning

confidence: 99%

A Revision of Wielandiella angustifolia, a Shrub-Sized Bennettite from the Rhaetian-Hettangian of Scania, Sweden, and Jameson Land, Greenland

Pott

2014

International Journal of Plant Sciences

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Editor: Patrick S. HerendeenPremise of research. The concept of Wielandiella angustifolia, a shrub-sized bennettite from the Rhaetian of southern Sweden and East Greenland, became the standard interpretation of the habit and plant architecture of the Williamsoniaceae during the last 100 years. This concept, however, was never critically reinvestigated to evaluate the validity of the restoration. In addition, the new International Code of Nomenclature for algae, fungi, and plants (Melbourne Code) allows erecting fossil taxa for whole-plant concepts, wherefore Wielandiella angustifolia is an ideal candidate.Methodology. The excellently preserved plant fossils were reinvestigated using modern methods, such as cuticular analysis and light, fluorescence, and scanning electron microscopy.Pivotal results. The reinvestigation led to the rejection of the bisexual nature of the plant and provides deeper insights into the plant's nature, biology, and ecology. The rejection of the bisexual nature necessitated emendation of the diagnosis of Wielandiella.Conclusions. The revised diagnosis circumscribes a whole-plant concept that includes branched axes bearing leaves, immature seed cones, and monosporangiate, flowerlike reproductive structures. Good candidates for the hitherto-unidentified microsporangiate structure and the mature seed cone are Bennettistemon and Vardekloeftia, respectively. Discussion of the results concluded that Wielandiella definitely forms a separate genus within the Williamsoniaceae that is distinct from Williamsoniella and Williamsonia.

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Section: Introductionmentioning

confidence: 99%

A Revision of Wielandiella angustifolia, a Shrub-Sized Bennettite from the Rhaetian-Hettangian of Scania, Sweden, and Jameson Land, Greenland

Pott

2014

International Journal of Plant Sciences

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“…However, the status of the name Monanthesia has long been a point of discussion, especially since Delevoryas (1959) regarded the name Monanthesia as invalidly published by Wieland (1934) and gave a new diagnosis. Most authors followed Delevoryas and refer to it as 'Monanthesia Wieland 1934 ex Delevoryas', e.g., Watson and Sincock (1992), Saiki and Yoshida (1999), Rothwell and Stockey (2002), and Watson and Lydon (2004). However, we are of a different opinion.…”

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confidence: 78%

A nomenclatural note on Monanthesia and Bennettites

Zijlstra¹,

Cittert

2014

Review of Palaeobotany and Palynology

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This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. This is a short nomenclatural note on the place of publication of Monanthesia and the lectotypification of Bennettites.© 2014 Elsevier B.V. All rights reserved.The name Monanthesia was introduced by Wieland (1934) for columnar bennettitalean stems with fructifications from the Upper Cretaceous of New Mexico (USA). In later years Monanthesia has also been described from the Lower and Upper Cretaceous of other parts of the world and additional species were recognized. However, the status of the name Monanthesia has long been a point of discussion, especially since Delevoryas (1959) regarded the name Monanthesia as invalidly published by Wieland (1934) and gave a new diagnosis. Most authors followed Delevoryas and refer to it as 'Monanthesia Wieland 1934 ex Delevoryas', e.g., Watson and Sincock (1992), Saiki and Yoshida (1999), Rothwell and Stockey (2002), and Watson and Lydon (2004). However, we are of a different opinion.Our first conclusion is that Delevoryas cannot be considered to have validated this name, because he had four species of which he thought he validly published the new name/a new combination. All this is, however, without designation of the type of the generic name, thus not fulfilling Art. 40.1 and 40.6 of the Melbourne Code (McNeill et al., 2012).Moreover, it does not appear to be necessary to start a search for the later validation of Monanthesia -thorough reading of Wieland's original publication revealed that this generic name was validly published in 1934! The only problem is that the generic diagnosis is not presented under a clear heading, but 'hidden' in the long text. On p. 94, Wieland (1934) gave a list of the occurrence "of Cycadeoids with flowers, fruits or flower-stalks in all the frond base axillae" (as such spaced by Wieland): six combinations in Cycadeoidea (occurring in N. America and Italy), followed by two in Monanthesia (M. blanca and M. magnifica from New Mexico). In the subsequent paragraph, this is stated: "The first six specimens 1 of this remarkable group to be recovered are known only from single isolated occurrences. But the forms from New Mexico include a varied and splendid series now well under way of elaboration. … In any case the cauliflorous types with fructifications in all frond axillae, have become a most imposing group, whether taken geographically, or geologically. Perhaps all the species should be included in some genus of convenience like the Monanthesia." Wieland was careful, placing in Monanthesia only the two species from New Mexico that were new and that he could well investigate: M. blanca and M. magnifica. In his textfig. 20 (to p. 115), a photograph of M....

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“…The other family in the Bennettitales is Cycadeoidaceae. Plants in this family are often bisexual and have an unbranched spherical stout trunk with dense leaf bases in a spiral arrangement, as well as a cone in the bract axil (Watson and Lydon, 2004;Taylor et al, 2010). The combination of characters possessed by the present fossils is consistent with assignment to the Cycadeoidaceae.…”

Section: Discussionmentioning

confidence: 99%

Anatomical Study of Cretaceous, Permineralized, Bennettitalean Fossils from Heilongjiang Province, NE China

Xiaonan

Cheng

2022

Acta Geologica Sinica (Eng)

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Well-preserved Cretaceous trunk fragments of Cycadeoidea (Cycadeoidaceae) were recently found in Keshan County, Heilongjiang Province, Northeast China. These fossils represent important evidence of the distribution of this group of plants in East Asia. In these trunk fragments, the stem cortices and leaf bases with cones are preserved. The leaf bases are rhombic with cones infrequently distributed among leaf bases. The cortex is broad and consists of fundamental parenchyma cells, numerous secretory ducts and C-shaped leaf traces with adaxial secondary xylem and abaxial secondary phloem. The genus Cycadeoidea, which is widely distributed in the Cretaceous deposits of East Asia, North America and Western Europe, was an important component of Cretaceous floras. Bennettitalean trunk fossils with well-preserved anatomical structures are rarely known from China. These fossils are important for studies of the evolution of genus Cycadeoidea and for stratigraphic correlation.

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The bennettitalean trunk genera Cycadeoidea and Monanthesia in the Purbeck, Wealden and Lower Greensand of southern England: a reassessment

Cited by 12 publications

References 29 publications

A Revision of Wielandiella angustifolia, a Shrub-Sized Bennettite from the Rhaetian-Hettangian of Scania, Sweden, and Jameson Land, Greenland

A Revision of Wielandiella angustifolia, a Shrub-Sized Bennettite from the Rhaetian-Hettangian of Scania, Sweden, and Jameson Land, Greenland

A nomenclatural note on Monanthesia and Bennettites

Anatomical Study of Cretaceous, Permineralized, Bennettitalean Fossils from Heilongjiang Province, NE China

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