A late Wenlock flora from Co. Tipperary, Ireland

Abstract

An iissemblagc of inacroplants preserved as highly coalified compressions which lack anatomy is described froin a Wenlock locality in County Tipperary, Ireland. Most of the fertile specimens are assigned to Goksonia Ling. l'hr taxonomic status of this genus is discussed. Some poorly preserved palynomorphs, including miospores, acritarchs, chitinozoans and a variety of tubes, have been isolated from associated sediments, hut the age of the flora is based on graptolites. Sedimentological and pa1;ieontologir;il stiidies of the region are summarized. They provide little direct evidence for the habitats of the plants which are considered to have been terrestrial. The relevance of this flora to the current debate on the colonization of the land is evaluated and it is concluded that these plants provide the earliest record of erect fertile land plants of possible pteridophyte affinity.

Thalloid carbonaceous incrustations and the asynchronous evolution of embryophyte characters during the Early Paleozoic

“…However, fossils of sporophytic axes of true bryophytes do not play much of a role in origin of land plant studies because they are so rarely preserved in the rock record. In any case, the fossil record of sporangiate axes commences in the Wenlock beginning with the occurrence of Cooksonia in Ireland (Edwards et al, 1983).…”

“…It has become increasingly evident over the past several decades that the record of land plant macro-(or, meso-) fossils does not extend below the Wenlock (Homerian) benchmark set by Edwards et al (1983). The scarcity of any Silurian deposits which contain fossil plants axes (see review by Edwards and Wellman, 2001) is enough to give one pause, because, from the standpoint of niche theory in evolutionary ecology (sensu Grinnell, 1928), one might naturally assume that as soon as the land plants originated, they would have quickly filled an initially empty global terrestrial niche.…”

A timeline for terrestrialization: consequences for the carbon cycle in the Palaeozoic

“…This is the case from the outset and persists throughout the Phanaerozoic. The oldest generally accepted record of a land plant body fossil is Cooksonia from the Silurian (Wenlock Series, Homerian Stage) of Ireland [19] (figure 2n,t). Other records of Cooksonia and Cooksonia-like plants are widespread through the Ludlow and Přidolí Series of Euramerica, Kazakhstan, China and Gondwana [10,20].…”

The first record ofCooksoniafrom South Americain Silurian rocks of Bolivia

“…) shares a border and sporangial outline with the Bolivian specimen and was also named C. cf caledonica. The new data from Bolivia indicate the widespread geographical distribution of Cooksonia, including its spread into higher latitudes soon after its appearance in the Wenlock (Edwards, Feehan & Smith, 1983). Finally, this discovery, together with numerous sterile axes from Negra Muerta and fossils from a second locality at Padcaya, south of Tarija, demonstrates the great potential of Bolivia for discovering more about global Silurian land vegetation.…”