2026/01/01 by Antoine Champreux, Brigitte Meyer‐Berthaud, Anne‐Laure Decombeix · 1 voice
Earth and Planetary Sciences · Agricultural and Biological Sciences · #Paleontology and Stratigraphy of Fossils #Paleontology and Evolutionary Biology #Plant Diversity and Evolution
paper · pdf · doi:10.26879/1640
The poor sampling of Late Devonian fossils in Gondwana prevents a full understanding of the diversification patterns of the main vascular plant groups that are ancestral to extant lineages, such as the different pteridophyte-grade lineages.Among these are the Iridopteridales, a group with architectural features comparable to those of the sphenophytes.The Famennian locality of Barraba in New South Wales has yielded a diverse plant assemblage, among which Keraphyton represents the first iridopterid genus recorded in Australia.In this paper, two anatomically preserved fragments of axes from Barraba are assigned to a new species of Keraphyton, K. talentii, and an emended diagnosis of this Australian genus is provided.The axes of K. talentii differ from K. mawsoniae in their smaller size, a primary vascular system organized around three fundamental ribs connected centrally, instead of four in K. mawsoniae, and a smaller number of ultimate ribs.The aerenchymatous cortex observed in some parts of K. talentii suggests that this species was able to live in temporarily, if not permanently, wet habitats.Keraphyton axes are characterized by a deeply lobed stele with a complex pattern of dissection, and protoxylem strands that tend to be exarch.The larger size of K. mawsoniae is associated with a higher number of primary xylem ribs, but the primary vascular system remains actinostelic and is not associated with the development of radially aligned tracheids.The new species increases the taxonomic diversity of the free-sporing plants that were already predominant in the permineralized plant assemblage of Barraba.