Palaeozoic Innovations in the Micro- and Megafossil Plant Record: From the Earliest Plant Spores to the Earliest Seeds

The palynological record across the Ordovician/Silurian boundary in the Cordillera Oriental, Central Andean Basin, northwestern Argentina

“…Such subjects have thereafter been reviewed and profusely discussed by different authors (e.g. Steemans et al, 2009Steemans et al, , 2010Steemans et al, , 2012Kenrick et al, 2012;Wellman et al, 2013Wellman et al, , 2015Edwards et al, 2014;Strother et al, 2015). Steemans (1999), Wellman and Gray (2000) and Steemans et al (2009) considered the cryptospores as dispersed spores derived from the earliest terrestrial flora represented by the primitive embryophytes.…”

The early land plants from the Armorican Massif: sedimentological and palynological considerations on age and environment

“…However, vascular plant megafossils appear later in the fossil record: the earliest fertile axial land plant fossil is reported from the Homerian (Middle Silurian;Edwards & Feehan, 1980). The Lower Devonian plantbearing deposits record some of the most striking changes occurring in the evolution of plants; by Emsian times, most major plant lineages were probably already established (Steemans et al 2010). The occurrence of deposits of this age is therefore of great importance for our knowledge of early land plants.…”

Palynology and palynofacies analysis of a Silurian (Llandovery–Wenlock) marine succession from the Precordillera of western Argentina: Palaeobiogeographical and palaeoenvironmental significance

“…Trilete spores have not been recorded so far in the La Chilca Formation, although they have been recorded in Llandovery and Wenlock marine deposits in other regions (Steemans et al, 2012). They were found in Hirnantian and Late Llandovery (Telychian) strata from Cordillera Oriental, northwestern Argentina .…”

“…Nevertheless, there are no meso-and megafossil plant records with lignified tissues from the Early Silurian, and it is probable that the vitrinite did not exist in the early stages of land plant evolution (Lüning et al, 2000). Even though the oldest trilete spores are known from the Katian (Steemans et al, 2009) and they are considered representative of the advent of vascular plants, true vascular plants or eutracheophytes with a thick lignified inner layer of conducting cells appear in the Lower Devonian (Steemans et al, 2012). Consequently, the possible presence of phytoclasts and vitrinite earlier than Devonian should be reconsidered.…”

“…This suggests that early land plants were geographically widespread due to their plasticity in adapting to different climates and environmental conditions during the Early Palaeozoic (Steemans et al, 2012;Rubinstein et al, 2015;Spina, 2015).…”