2002/06/01 by Michele E. Kotyk, James F. Basinger, Patricia G. Gensel +1 · 3 citations
Earth and Planetary Sciences · Agricultural and Biological Sciences · #Geological Studies and Exploration #Plant Diversity and Evolution #Paleontology and Stratigraphy of Fossils #Macrofossil #Biology #Arctic #Plant evolution #Paleontology #The arctic #Botany #Evolutionary biology #Ecology #Pollen #Oceanography #Genetics #Gene
paper · pdf · doi:10.3732/ajb.89.6.1004
openalex publication_date 2002/06/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In addition to vegetative remains, fertile remains from ten plants, representing seven distinct taxa whose size and complexity are much greater than most contemporaneous fossils, are reported from late Ludlow (Ludfordian) sediments of Bathurst Island in Nunavut, Canada. Evidence for the age of these beds is gathered from stratigraphic relationships and index fossils including conodonts, graptolites, and brachiopods. Zosterophylls dominate the collection, some of which constitute the earliest record of fertile structures arranged in dense clusters and longitudinal rows along axes. Representatives include a plant that resembles Bathurstia, one species of Zosterophyllum, and two specimens that bear affinity to this genus. Distichophytum is also represented, as is a new zosterophyll named Macivera gracilis. The prevalence of sporangial clustering and reduced sporangial stalks in this flora leads to a discussion of the origins and significance of these morphological features. Following a review of some of the other Silurian floras, particularly the Baragwanathia-bearing Lower Plant Assemblage of Victoria, Australia, which also shows morphological advancement over the rhyniophytoid-dominated floras common to Laurussia, it is concluded that the Bathurst Island flora presents the best evidence to date of substantial morphological diversity, complexity, and stature of vascular land plants in this period.