Fossil Cone Scale Of Conifer From The Early Cretaceous In Huolinhe Basin Of Inner Mongolia And Its Paleoenvironmental Significance

The Lower Cretaceous with abundant plant fossils develops well in Inner Mongolia, China and the Huolinhe Basin is one of the typical regions contain the Early Cretaceous strata. One species of cone scale fossil, which was well-preserved and collected from the Huolinhe Formation of Lower Cretaceous, Huolinhe Basin, Inner Mongolia, was studied on the macro-characteristics and epidermal microstructure in the paper. It reveales that the fossils are ovate-oblong in shape, the upper-middle part of fossil is widest and the ratio of length and width about 2.34, the top rounded, the base taper or obtuse, longitudinal grains are light, the trace of seed unseen. The cells rectangle, square or polygon, the anticlinal wall straight, the end wall tilt, and cells were arranged in linear, stomata scattered, stoma opened, and subsidiary cells arranged in ring around the guard cells. All characteristics were quite different from all other known species of Pityolepis, named as one new species Pityolepis huolinhensis Yao sp. nov. The data of length and width from 37 fossil specimens was processed and analyzed by the linear regression of mathematical statistics. The results showed that the fitting degree was moderate, the linear correlation existed between length and width, the linear relationship formula was y=10.84817+0.723751x. According to the lithology of fossil preserved bed and fossils, it is considered that present fossils might be nearly autochthonous buria. And the sedimentary environment of the fossil strata might be swamp, the parent plant of cone scale fossils might grow near the water of swamp. Assemblage of fossil plants shows that the paleoclimate of Huolinhe Basin was warm and humid in the Early Cretaceous. The paper provides reference for the fossil research on the microstructure of cone scale reproductive organs also.