The Epidermal Structure Of Yanliaoa, From Middle Jurassic In Daohugou Of Ningcheng, Inner Mongolia

Yanliaoa is a common genus of fossil plant in Middle Jurassic of the west ofLiaoning, Inner Mongolia and north Hebei province, it is also one of the importantmember of the Yanliao biota. The genus was founded by Pan in1977based on thetype specimen from Middle Jurassic Haifanggou formation in Huludao, the west ofLiaoning. Only have found one species (Y. sinensis) till now.Since the genus was founded, Pan(1977), Wang(1984), Yang(1985),Zhang&Zheng(1987) and Sun et al(2011) had reported on it for its stratum, branchesand leaves form, classification and the plants living with it. However, the epidermalstructure of Yanliaoa has never been reported before.This paper studies the epidermal structure of Yanliaoa by using cuticle techniquebased on chemical treatment for2specimens with cuticle, and making use of a newtechnique to supplement for the specimens without cuticle preserved(The newtechnique for deciphering the epidermal structure of fossil plants was introduced inour nearly published paper for the sample without cuticle preserved); After theepidermal structure acquired, we describe it in detail and compared it with9genus ofTaxodiaceae(especially with Sequoia) that are still living today to get moreinformation about Yanliaoa.Though Pan(1977) has proposed that Yanliaoa might be the direct ancestor ofSequoia, the assumptions has never been proved by epidermal structure information.This paper supplies the epidermal structure of Yanliaoa, and compares the two genus,the result clearly shows that the epidermal structure of Yanliaoa appears to bedifferent from of Sequoia in stomatal bands and stomatal apparatus.The research work reported in this thesis provides new data for the study ofMiddle Jurassic floras in the North China, and it would also be more significant forthe study of the paleogeography and paleoclimate during the Middle Jurassic time inthe studied areas.