【摘要】 新疆塔里木盆地西北缘大湾沟剖面晚奥陶世地层发现保存良好的疑源类组合。该组合包括17属27种,以棘刺类(特别是Baltisphaeridium)占优势;其次为梭形类,以Navifusa为代表。大湾沟疑源类组合与世界其它地区同期组合对比表明,在晚奥陶世时疑源类古生物地理分区性减弱,不及早—中奥陶世明显。该组合中有13个种仅分布于“Caradoc”—“Ashgill”期,地理分布广泛,因而颇具生物地层学潜力。更多还原

【Abstract】 A well-preserved and diverse acritarch assemblage was recovered from four Upper Ordovician formations of the Dawangou section, Xinjiang, northwestern China (Tarim Block). This palynomorph assemblage consists of 27 species assigned to 17 genera. The palynomorph assemblage is dominated by acanthomorphic acritarchs (particularly species of Baltisphaeridium), followed by netromorphs, represented by Navifusa. Comparison of the palynomorph assemblage with correlative age assemblages elsewhere supports the observation that there was little faunal or floral provincialism during the Late Ordovician. In addition, 13 species recovered from the Dawangou section are restricted to the Caradoc—Ashgill, and have a wide geographical range making them useful biostratigraphical taxa.更多还原