摘要
甘肃马鬃山地区早白垩世地层发育,富含植物化石,但研究程度相对较低。本文综合多种方法对甘肃马鬃山地区下白垩统赤金堡组所产出的裸子植物种子化石进行了详细的形态学及解剖学研究。利用体式显微镜及X射线断层扫描成像技术对其形态特征展开对比研究;利用光学显微镜,荧光显微镜和扫描电子显微镜对其表皮微细构造进行了细致观察对比。认为,当前种子化石形态为椭圆形或卵圆形,表面光滑或有细纹,与裸子植物种子化石Carpolithus形态特征吻合,故将其分别鉴定为Carpolithus mazongshanensissp. nov.(马鬃山石籽)和Carpolithuscf.jidongensis(鸡东石籽相似种)。其中C.mazongshanensis sp. nov.种子卵圆形,顶端具尖喙,基部浑圆,表面具弧状平行的纵纹,种皮外角质层细胞呈长条形;珠心角质层细胞近正方形或多边形。C.cf.jidongensis种子长卵形,顶端钝尖,基部渐狭,两侧具弧形纵纹,种皮外角质层细胞呈长条形。通过与现生裸子植物种子形态及表皮特征的对比分析,本次发现的石籽属化石归属于柏科,推测可能与侧柏属亲缘关系较近。
The Lower Cretaceous deposits in the Mazongshan area of Gansu Province are rich in plant fossils, which are poorly studied. In this paper, detailed morphological and anatomical studies were conducted on the gymnosperm seed fossils collected from the Lower Cretaceous Chijinbao Formation in the Mazongshan area, Gansu Province. The morphological structures are observed by using stereomicroscope and X-ray tomography, and the cuticular micro-structures are observed by using light microscope, fluorescence microscope and Scanning Electron Microscope. The present gymnosperm seed fossils are charactered by elliptical or oval-shaped, smooth or with longitudinal grains on the surface, which is consistent with the fossil genera Carpolithus, and were identified as Carpolithus. Carpolithus is elliptical, oval or spindle-shaped with smooth or ornamental surface. The numerous gymnosperm seed fossils present were identified as Carpolithus mazongshanensis sp. nov. and Carpolithus cf. jidongensis respectively. C. mazongshanensis sp. nov. is oval shaped, beaked apically and rounded basally, with arc-shaped parallel longitudinal grains on the seed surface. The outer stratum corneum cells of the seed coat were elongated;the stratum corneum cells were nearly square or polygon. C. cf. jidongensis is oblong ovate shaped, obtuse apically and narrows gradually at the base, with arc-shaped longitudinal grains on the seed sides. The outer stratum corneum cells of C. cf. jidongensis seed coat are elongated. Based on the contrastive analysis of both morphology and epidermal characters with extant gymnosperm seeds, C. mazongshanensis sp. nov. and C. cf. jidongensis may be closely related to Platycladus.
作者
李爱静
惠建国
马国荣
王森
张静
雷向通
杜宝霞
LI Aijing;HUI Jianguo;MA Guorong;WANG Sen;ZHANG Jing;LEI Xiangtong;DU Baoxia(School of Earth Sciences,Lanzhou University,Lanzhou,Gansu 730000,China;Yunnan Key Laboratory for Palaeobiology,Institute of Palaeontology,Yunnan University,Kunming,Yunnan 650500,China)
出处
《地质学报》
EI
CAS
CSCD
北大核心
2021年第5期1400-1413,共14页
Acta Geologica Sinica
基金
第二次青藏高原科学考察项目(编号2019QZKK0704)
国家自然科学基金项目(编号42072014、41872010)
中央高校基础研究经费项目(编号Lzujbky-2019-45)联合资助的成果。
