摘要
Abundant and well-preserved organic-walled microfossils including acanthomorphic acritarchs have been found in Mesoproterozoic Beidajian Formation in the Yongji area of Shanxi Province, North China. The morphological and ultrastructural features of these acanthomorphic acri-tarchs resemble living dinoflagellates (e.g. double-walled and polygonal structures), which leads to the interpretation of these fossils as probably the oldest dinoflagellates. The detec-tion of dinosterane, a dinoflagellate biomarker, from pyro-lytic product of these fossils further supports the morpho-logical inference. This finding is consistent with molecular clock estimate that dinoflagellates may have diverged 700 to 900 million years (Ma) before previously known fossil re-cord.
Abundant and well-preserved organic-walled microfossils includingacanthomorphic acritarchs have been found in Mesoproterozoic Beidajian Formation in the Yongji areaof Shanxi Province, North China. The morphological and ultrastructural features of theseacanthomorphic acritarchs resemble living dinoflagellates (e.g. double-walled and polygonalstructures), which leads to the interpretation of these fossils as probably the oldestdinoflagellates. The detection of dinosterane, a dinoflagellate biomarker, from pyrolytic product ofthese fossils further supports the morphological inference. This finding is consistent withmolecular clock estimate that dinoflagellates may have diverged 700 to 900 million years (Ma) beforepreviously known fossil record.
基金
supported by the National N atural Science Foundation of China(Grant No.40472003)
the Ministry of Science and Technology of China(Grant Nos.G2000077701 and 2003CB7 16805)
the Chinese Academy of Sciences(Grant No,KZCX3-SW-141).
关键词
腰鞭毛虫
形态学
中元古代
化石
Mesoproterozoic
Beidajian Formation
acanthomorphic acritarch
dinoflagellate
dinosterane
