Sprecher
Beschreibung
Antarctica was home to extensive forest ecosystems during the Late Cretaceous. While a rich diversity of vascular plants have been identified from Upper Cretaceous deposits in West Antarctica, only a handful of bryophyte families have been reported. Here we provide a preliminary report of a rich permineralized bryoflora from the Campanian Sitio Feliz and Baculites Hill localities on James Ross Island, Antarctica. Importantly, the mode of preservation of plants from these localities allows us to observe important anatomical details and microbial associations. Fossil bryophytes from these localities are primarily mosses and are found in calcium carbonate concretions as isolated gametophytes or in dense concentrations comprising dozens of individual gametophytes. Bryophyte concentrations are roughly 5×5 cm and superficially resemble moss mats that are of a size, frequency, and diversity not yet documented in the fossil record. There are over a dozen novel moss and liverwort morphotypes in these concentrations. Preliminary taxonomic analysis suggests that some of these morphotypes belong to Grimmiaceae and Dicranaceae. Isolated gametophytes expand the taxonomic diversity of this fossil bryophyte flora and include Rhabdoweisiaceae. Several isolated gametophytes have well-preserved gametangia. Furthermore, several mosses have epiphytic microbes on leaf surfaces. While palynological studies of Upper Cretaceous deposits in West Antarctica typically only reveal a few bryophyte clades (e.g., Sphagnaceae, Ricciaceae, and Sphaerocarpales), the permineralized flora from the Sitio Feliz and Baculites Hill localities strongly indicates that mosses were diverse elements of the Late Cretaceous polar forests of Antarctica.