Abstract: Investigation of the Mesozoic seed plant Leptostrobus Heer from the Yangcaogou Formation of the Late Triassic and the Yixian Formation of the Early Cretaceous, Liaoning Province, China, provides new insight into its general morphology and geographical distribution. The materials of L. cancer from the Yixian Formation described herein are later than all the past findings of this species and add to the record of L. cancer during the Early Cretaceous. Based on well-preserved specimens, the specific diagnosis is slightly emended and the reconstruction of L. cancer is perfected. The materials from the Yangcaogou Formation of the Late Triassic are placed in L. sphaericus. In addition, we review the history of investigation of the genus Leptostrobus since its establishment in 1876 and discuss the main characteristics of each species.(Author for correspondence.Tel: 010 6283 6436; Fax: 010 6259 3385; E-mail: lics@ibcas.ac.cn)

Key words: Early Cretaceous, Late Triassic, Leptostrobus, Yangcaogou Formation, Yixian Formation.