Sprecher
Beschreibung
Excellently preserved, articulated plant fossils from the Oxfordian (Upper Jurassic) Tochikubo Formation in Northeast Japan provide critical insights into the diversity and reconstruction of whole-plant bennettites. Based on these discoveries, two distinct taxa were most recently described and reconstructed. First, Ohaniella ptilofolia gen. et sp. nov. is established based on preserved axes with attached Ptilophyllum jurassicum-type foliage and apical ovuliferous structures. The co-occurrence of Weltrichia-type microsporangiate flowers suggests they were shed after maturity, and that O. ptilofolia likely formed monotypic shrub thickets under specific environmental conditions. Second, Kimuriella densifolia gen. et sp. nov. is described and restored based on organic connections between axes, sterile foliage (identical to isolated Zamites nipponicus), and ovuliferous Williamsonia-type flowers. Its associated Weltrichia-type microsporangiate flowers strongly warrant conspecificity. The unique combination of a divaricate growth habit and Zamites-type foliage necessitated the erection of the new genus Kimuriella. Detailed nomenclatural comparisons are made with coeval European bennettites, specifically Williamsonia gigas and Williamsonia pecten from the Bajocian of Yorkshire, UK, addressing the limitations and classical circumscriptions of form-classification for isolated fossil organs. Finally, this study discusses the palaeo-ecological interpretations of the coastal or river delta environments where these two bennettitalean species thrived, enhancing our understanding of Upper Jurassic terrestrial ecosystems in East Asia.