New Observations on Leptophloeum rhombicum from the upper Devonian of Hubei, China Anatomical Structures of Microsporangiate Cone of Lepidodendrales-- Lepidos trobus Shanxiense sp. nov. Diaphorodendron rhombicum sp. nov., a New Anatomically Preserved Lepidodendralean Stem from the Taiyuan Formation in Southern Shandong Province, North China