摘要
广西天等把荷剖面下泥盆统埃姆斯阶产较丰富的Polygnathus属牙形刺化石。经详细鉴定,共识别出Polygnathus inversus,Pol.gilberti,Pol.laticostatus,Pol.linguiformis bultyncki,Pol.nothoperbonus,Pol.perbonus,Pol.serotinus,Pol.vigierei等11种(含1个未定种和2个相似种)。根据牙形刺的特征和地层分布,自下而上划分为3个牙形刺带,即nothoperbonus带、inversus带和serotinus带。在系统分类研究的基础上,根据剖面中牙形刺产出层位及齿台口面和反口面特征分析,Pol.serotinus可能由Pol.vigierei通过外齿台边缘的抬升、外侧近脊沟的变宽变深以及齿台前缘的逐渐平行演化而来,Polygnathus属反口面基腔翻转的特征最早出现在Pol.nothoperbonus演化阶段。
Abstract Abundant Emsian （Lower Devonian） cono- donts are yielded in Bahe section, Tiandeng coun- ty, Guangxi. Eleven Polygnathus taxa are identi- fied, from which one is unnamed and two are inde- terminate, including Polygnathus inversus , Pol. gilberti, Pol. laticostatus, Pol. lingui formis bul- tyncki , Pol. nothoperbonus, Pol. perbonus, Pol. serotinus, Pol. vigierei, and can be assigned asthe nothoperbonus, inversus and serotinus zones in ascending order. According to the oral and aboral characters and stratigraphic distributions, it is suggested in Bahe section that Pol. serotinus de-rives from Pol. vigierei by the elevation of the outer platform margin, deepening and broadening of the outer adcarinal trough, and by becoming more and more parallel to the anterior platform margins. What＇s more, the inversion of basal cav- ity in Polygnathus firstly commences during the evolutionary stage of Pol. nothoperbonus.
出处
《古生物学报》
CAS
CSCD
北大核心
2013年第3期309-330,共22页
Acta Palaeontologica Sinica
基金
国家自然科学基金(40872009)
中国科学院南京地质古生物研究所"一三五"部署项目联合资助
