陕西商南两岔口组牙形刺化石的发现

THE DISCOVERY OF CONODONTS FROM LIANGCHAKOU FORMATION IN SHANGNAN COUNTY SHAANXI PROVINCE

首次报道了东秦岭造山带奥陶系两岔口组中的牙形刺化石９个属。其组合面貌具有中奥陶世晚期牙形刺的特色，总体可与河南荆关一带寺岗组和陕西耀县一带桃启坡组中的牙形刺对比。

This paper reports for the first time some conodonts from the Liangchakou formation of Ordovician period in the eastern Qinling orogenic belt, Shangnan county, Shaanxi province, including 9 genera, 3 species and 6 species indeterminata. These conodonts have a social characteristics of late stage of middle Ordovician conodonts. They can be correlated with those from the Sigang formation in Jinguan, Henan Province and the Taoqipo Formation in Yaoxian, Shaanxi Province.