蒙古南戈壁泥盆纪(埃姆斯期—艾菲尔期)牙形刺(英文)

DEVONIAN (EMSIAN—EIFELIAN) CONODONTS FROM SOUTH GOBI, MONGOLIA

在蒙古南戈壁地区丘隆组(Chuluun Formation)和查干卡勒噶组(Tsagaankhaalga Formation) 发现的牙形刺证明丘隆组的时代为晚埃姆斯期,查干卡勒噶组的时代为早艾菲尔期,与以前大化石所确定的时代一致。但艾菲尔阶的底界暂时还无法准确确定,蒙古南戈壁地区艾菲尔阶牙形刺动物群与同期北美的牙形刺动物群相似,但也包含一些地方性分子,蒙古海相艾菲尔期的沉积可能不完整。本文描述了2 个命名新种,Caudicriodus delicatus sp. nov., C. paraculicellus sp. nov.,一个未命名新种,Caudicriodus sp. nov. A 和一个新亚种, Cuadicriodus angustus cauda subsp. nov.。

Conodonts have been found from the Chuluun and Teagaankhaalga formations and verify that the Chuluun Formation is late Emsian and the Tsagaankhaalga Formation is Early Eifelian as previously dated by macrofossils.However, the lover boundary of the Eifelian cannot be precisely defined at this time. Mongolian Eifelian conodont faunas are very similar to those of North America, but also contain some endemic elements. The Eifelian marine de-posits in mongolia are probably incomplete.Two named new species, Caudicriodus declinatus sp.nov., Caudicriodus paraculicellus sp. nov., one un-named species, Caudicriodus sp. nov. A, as well as one new subspecies, Caudicriodus angustus cauda subsp. now., are described in this paper.