中国科学院南京地质古生物研究所机构知识库

The eusporangiate fern order Marattiales are represented in the living flora by the family Marattiaceae but have an extensive fossil record stretching back to the Carboniferous. The family Psaroniaceae included important wet-land plants in the Carboniferous and Permian. In this work we present a new member of the Psaroniaceae from the Lloyd Cove Seam of the Brogan's Mine, Sydney Coalfield, Nova Scotia, Canada dated to the Kasimovian Stage (lower Stephanian, Pennsylvanian) of the Carboniferous. The new fern is represented by a small specimen with distinctive fertile pinnules and reproductive organs including large synangia that possess a well-developed synangial sheath with a central parenchymatous filling. Small monolete in situ spores are compared to the dis-persed miospore species Punctatosporites pygmaeus. Based on well preserved reproductive organs, we are pro-posing a new species Diplazites campbellii sp. nov. A new evolutionary model combining species that produced the smallest monolete spores and significant characters of their reproductive organs is suggested. Four following subgroups are suggested: the Unita, Hemitelioides, Multisporangiate and Crenulopteris. (c) 2023 Published by Elsevier B.V.