A male cone of Pseudofrenelopsis dalatzensis with in situ pollen grains from the Lower Cretaceous of Northeast China

作者：Yang Xiao Ju^*

来源：Geobios, 2008, 41(5): 689-698.

DOI：10.1016/j.geobios.2008.03.001

• Classopollis
• Pseudofrenelopsis
• Cheirolepidiaceae
• Cretaceous
• China

A Classopollis-containing male cone found in close association with Pseudofrenelopsis dalatzensis from the Lower Cretaceous Dalazi Formation of Yanji Basin, eastern Jilin, China was studied using scanning electron microscopy and described as Classostrobus dalatzensis sp. nov. The small oval cone, borne on the top of a stalk (fertile short shoot), consists of helically arranged microsporophylls, each with a rhomboid and expanded distal head. The short shoot is divided into indistinct nodes and internodes with fine longitudinal striations. Cuticles of the microsporophyll and the internode of the short shoot are generally similar to Pseudofrenelopsis dalatzensis internode cuticles, all of them having papillate outer surfaces. Stomata are similar in structure and arrangement, with papillae of subsidiary cells overhanging the stomatal pit. Epidermal cells are rectangular or isodiametrical, each with a robust papilla on the periclinal wall. Hypodermal cells are present between the stomatal files. The internal structure of the in situ Classopollis pollen grains was studied in detail. Pollen grain is small, with thin sexine, poorly developed nexine and may be immature. This is the first record of in situ pollen grains Classopollis in China of which the internal structure is known in detail.

• 出版日期2008-10
• 单位中国科学院