Whole-Plant Reconstruction and Phylogenetic Relationships of Elatides zhoui sp. nov. (Cupressaceae) from the Early Cretaceous of Mongolia

Abstract

Premise of research. Exceptionally well-preserved lignified fossils from the Early Cretaceous of Mongolia include abundant conifer leafy shoots with attached pollen cones and seed cones. A whole-plant reconstruction based on these fossils enables a critical evaluation of the relationship of this extinct plant with extant conifers.Methodology. Bulk lignite samples collected from the Tugrug lignite mine were disaggregated in water, cleaned with hydrochloric and hydrofluoric acids, washed, and dried in air. Fossils were then examined using light and scanning electron microscopy.Pivotal results. Elatides zhoui sp. nov. has helically arranged leaves with two narrow lateral stomatal bands, predominantly on the adaxial leaf surface. Pollen cones are usually borne laterally on shoots in tight spirals; each microsporophyll bears three pollen sacs that produce nonsaccate pollen with a small circular aperture. Seed cones have numerous bract-scale complexes, each with a small membranous ovuliferous scale and four to ...