Early land plants from the Late Silurian-Early Devonian of Bathurst Island, Canadian Arctic Archipelago

Approximately 86 specimens of Bathurstia denticulata Hueber were collected from upper Bathurst Island and lower Stuart Bay beds of Bathurst Island, Canadian Arctic Archipelago. Bathurstia was a component of a zosterophyll-dominated flora of Pragian age (Lower Devonian) that existed at low paleolatitudes in northern Canada. The large collection of well-preserved materials permits reconstruction of the plant as a robust scrambler of about 30 cm in height. Stems bear short, shelf-like emergences in two rows, and branch isotomously, although sparsely. Rooting organs, representing some of the oldest known for land plants, arise from the main aerial axes, although they are also associated with small, subordinate shoots interpreted as plantlets. Numerous specimens are fertile, with sporangia borne in dense terminal spikes. Spikes include two rows of overlapping, discoid sporangia. Isospores are round and featureless, and assignable to the genus Calamospora. While Bathurstia apparently originated from among the isotomously branching bilaterally symmetrical zosterophylls, the phylogenetic relationships of Bathurstia to known taxa is unclear, although some resemblance to Serrulacaulis, Barinophytaceae, and the Gosslingiaceae can be documented. Bathurstia denticulata is now one of the best known of early land plants, and contributes significantly to our understanding of zosterophylls and their role in Early Devonian vegetation.Key words: Bathurstia, zosterophyll, Devonian, Canada, Arctic, evolution.

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The dawn of symbiosis between plants and fungi

Biology Letters ◽

10.1098/rsbl.2010.1203 ◽

2011 ◽

Vol 7 (4) ◽

pp. 574-577 ◽

Cited By ~ 156

Author(s):

Martin I. Bidartondo ◽

David J. Read ◽

James M. Trappe ◽

Vincent Merckx ◽

Roberto Ligrone ◽

...

Keyword(s):

Vascular Plant ◽

Land Plants ◽

Evolutionary Trees ◽

Early Devonian ◽

Present Evidence ◽

Plant Fossils ◽

Biological Innovations ◽

New Hypothesis ◽

Colonization Of Land ◽

Early Land

The colonization of land by plants relied on fundamental biological innovations, among which was symbiosis with fungi to enhance nutrient uptake. Here we present evidence that several species representing the earliest groups of land plants are symbiotic with fungi of the Mucoromycotina. This finding brings up the possibility that terrestrialization was facilitated by these fungi rather than, as conventionally proposed, by members of the Glomeromycota. Since the 1970s it has been assumed, largely from the observation that vascular plant fossils of the early Devonian (400 Ma) show arbuscule-like structures, that fungi of the Glomeromycota were the earliest to form mycorrhizas, and evolutionary trees have, until now, placed Glomeromycota as the oldest known lineage of endomycorrhizal fungi. Our observation that Endogone -like fungi are widely associated with the earliest branching land plants, and give way to glomeromycotan fungi in later lineages, raises the new hypothesis that members of the Mucoromycotina rather than the Glomeromycota enabled the establishment and growth of early land colonists.

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, an Early Devonian plant from Yunnan Province, China and its bearing on some structures of early land plants

Review of Palaeobotany and Palynology ◽

10.1016/0034-6667(92)90160-i ◽

1992 ◽

Vol 71 (1-4) ◽

pp. 121-147 ◽

Cited By ~ 24

Author(s):

Cheng-Sen Li

Keyword(s):

Yunnan Province ◽

Land Plants ◽

Early Devonian ◽

Early Land

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Early land plants

Philosophical Transactions of the Royal Society of London Series B Biological Sciences ◽

10.1098/rstb.1985.0078 ◽

1985 ◽

Vol 309 (1138) ◽

pp. 197-200 ◽

Cited By ~ 2

Keyword(s):

New York ◽

Land Plants ◽

Early Devonian ◽

Present Evidence ◽

Rhynie Chert ◽

Terrestrial Fungi ◽

Early Land

After three decades of vigorous research on the Siluro-Devonian floras neither interest nor productivity is slackening. Some newer developments and comments on the two previous papers are listed here to highlight the varied disciplines and approaches that are being brought to bear on Silurian-early Devonian floras. (i) Banks (1981) reported wounds, probably inflicted by chewing microarthropods, in axes of Psilophyton dawsonii repaired by the form ation of a periderm . Unreported evidence indicates wounding and repair stimulated by piercing and sucking activity of other animals. These observations complement the work of Kevan et al. (1975) on arthropods and damage to plants that are found in the Rhynie Chert, and that of Shear et al . (1984) on a new terrestrial fauna from eastern New York. Interest in plant-anim al interrelationships will attract a new group of scholars to the study of Siluro-Devonian plants. Particularly im portant will be the m aceration of large quantities of rock. (ii) Stubblefield & Banks (1983) found oomycetous fungi within cells in the cellularly perm ineralized aerial axes of Psilophyton dawsonii . Rayner (1983) reported apparent fungal bodies in the spines on compression specimens of Sawdonia ornata . These reports supplem ent that by Kevan et al . (1975) on the fungi in the Rhynie Chert. Whether the fungi were parasitic or saprophytic, or were mycorrhizal as suggested by Pirozynski & Malloch (1975), is unclear on the basis of present evidence. Sherwood-Pike & Gray (1985) have isolated hyphae and spores of higher fungi from macerates of mid to late Silurian rocks from Gotland. Other fragments appear to be coprolites of arthropods that include fragments of hyphae. They suggest that fungi and microarthropods may have served as terrestrial decomposers during late Silurian. Pratt et al. (1978) reported septate fungi in earliest Silurian. These introductory works imply a productive future in the study of Siluro-Devonian terrestrial fungi.

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Notes on Early Land Plants Today. 51. Validation of Schistochilopsis hyperarctica (Scapaniaceae, Marchantiophyta)

Phytotaxa ◽

10.11646/phytotaxa.162.4.10 ◽

2014 ◽

Vol 162 (4) ◽

pp. 240 ◽

Cited By ~ 3

Author(s):

Nadezda A. Konstantinova ◽

Lars Söderström ◽

Anders Hagborg ◽

Matt Von Konrat

Keyword(s):

Small Area ◽

Canadian Arctic ◽

Ellesmere Island ◽

Land Plants ◽

Collection Number ◽

Small Collection ◽

Early Land

Lophozia hyperarctica (Schuster 1961: 967) was described from Ellesmere Island, Canadian Arctic. However, the author stated that the species occurred in very small patches and made a collection of them in a small area, but giving every small collection a separate collection number, thus making several gatherings out of them. When describing the species he used 5 differently numbered gatherings stating “these five collections extremely skimpy, coming from the same locality and to be considered the collective representing the type” thus violating ICN Art. 41.2 (McNeill et al. 2012). This mistake was overlooked when transferring the taxon to Massula hyperarctica (R.M.Schust.) Schljakov (1972: 318), Massularia hyperarctica (R.M.Schust.) Schljakov (1985: 232), Schistochilopsis hyperarctica (R.M.Schust.) Konstant. in Konstantinova & Vasiljev (1994: 125) and Lophozia grandiretis var. hyperarctica (R.M.Schust.) Damsholt (2008: 98). The species is validated here.

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Implications of Early Devonian poles from the Canadian Arctic Archipelago for the North American apparent polar wander path

Canadian Journal of Earth Sciences ◽

10.1139/e82-159 ◽

1982 ◽

Vol 19 (9) ◽

pp. 1802-1809 ◽

Cited By ~ 24

Author(s):

Peter Dankers

Keyword(s):

North American ◽

Canadian Arctic ◽

Canadian Arctic Archipelago ◽

Early Devonian ◽

Polar Wander ◽

The North ◽

Apparent Polar Wander Path ◽

Late Cambrian ◽

Normal Polarity ◽

North American Craton

Lower Devonian red beds from the upper member of the Peel Sound Formation at Prince of Wales Island (Canadian arctic) yield two different paleopoles at 25N 099E and at 01N 091E, the first one being older than the second one. The magnetic directions from which the poles are calculated are derived from vector analysis of thermal, chemical, and alternating magnetic field demagnetization results. Normal and reversed polarities are recorded for the northerly pole, whereas the pole at the equator reveals mainly a normal polarity. The position of the pole close to the equator has significant implications for the early Paleozoic apparent polar wander path of the North American craton. It appears that from the Late Cambrian to Early Devonian the craton moved continuously in a counter-clockwise direction that ended abruptly in the Early Devonian when the direction of the motion of the continent was reversed in a very similar manner to what occurred in Late Cambrian times.

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