New data on the Mesozoic conifer genus Sciadopityoides Sveshnikova (Miroviaceae)

The paper documents in detail the morphological and epidermal characters of the leaves of the Mesozoic conifer genus Sciadopityoides Sveshnikova based on the investigation of specimens from the north of East Siberia, the Urals, Ukraine and Greenland. For the first time, the leaf epidermal structures in this genus were studied with the scanning electron and the laser confocal microscopes. The species originally described as Sciadopitys arctica Abramova and Sciadopitys swetlanae Kiritchkova are shown to be identical with, respectively, Sciadopityoides crameri (Heer) Sveshnikova and Sciadopityoides brevifolia (Abramova) Hvalj. Emended descriptions are provided for Sciadopityoides ukrainensis (Doludenko) Sveshnikova and S. brevifolia; a diagnosis, missing in the original publication, is given and a lectotype is selected for S. brevifolia and an emended diagnosis is suggested for S. ukrainensis.