本文报道了在桂东仁义剖面中上泥盆统巴漆组中一段八十余米厚地层中发现的牙形石 3 属 10 种(包括亚种) 和腕足动物 16 属 17 种(包括属种未定类型)。根据牙形石的组合分布, 识别出 Schmidtognathus hermanni 带、 Polygnathus cristatus 带和 Klapperina disparilis 带上亚带, 表明研究层段属于中泥盆统吉维特阶上部。该段地层顶底各有 1 层腕足化石富集层, 代表了该剖面上 2 个不同的腕足动物化石组合。下化石层位于 S. hermanni 带内, 主要由 Leiorhynchus kwangsiensis 组成, 属种组成单一, 其发现确认了 Leiorhynchus 在华南中泥盆统中的存在。上化石层位于 K. disparilis 带上亚带内, 腕足动物属种组成众多, 至少有 15 属, 是目前已知在华南地区单个剖面上发现的吉维特阶上部腕足化石种类最多的化石层。在动物群组成上, 以小嘴贝类分子占优, 石燕贝类和无洞贝类次之, 兼有其他类群, 但缺乏无窗贝类。在标本数量上, 以 Gypidula、Coeloterorhynchus 和 Spinatrypina 等分子占优。

The Renyi Section is a newly discovered section in the vicinity of Renyi Town, Hezhou City of Guangxi, in which a continuous marine sedimentary succession of the Middle and Upper Devonian is well developed and out-cropped. The succession yields abundant benthic and pelagic fossils. This paper presents a preliminary research resulton the conodonts and brachiopods from the middle part of the Middle-Upper Devonian Baqi Formation (ca. 80 m thick) at this section. Ten species (or subspecies) of three genera of conodonts are recognized from the studied interval, including Polygnathus alatus, P. cf. collieri, P. cristatus, P. dubius, P. dengleri, P. dengleri sagitta, P. webbi, P. xylus, Klapperina disparalvea and Schmidtognathus wittekindti. Seventeen species of 16 genera of brachiopods are also reported herein, including Schizophoria sp., Gypidula sp., productoid gen. et sp. indet., Leiorhynchus kwangsiensis, Coeloterorhynchus sp., Hypothyridina sp., Uncinulus? sp., Fitzroyella sp., “Ypsilorhychus” subellipticus, Desquamatia sp., Spinatrypina douvillii, Spinatrypina sp., Emanuella sp., Mucrospirifer sp., Undispiriferoides tianqipuensis, Cryptonella? sp. and Oligothyrina? sp. According to the distribution of the conodonts, three conodont zones (S. hermanni, P. cristatus and K. disparilis zones) have been recognized from the studied interval, suggesting an age of late Givetian of the Middle Devonian. The brachiopods were mainly collected from two fossiliferous layers near the base and top of the studied interval, representing two different brachiopod assemblages. The brachiopod fauna from the lower fossiliferous layer (ca. 20 cm thick, S. hermanni Zone) is relatively monotonous in composition, mainly consisting of L. kwangsiensis. This finding verifies the Middle Devonian occurrence of the genus Leiorhynchus in South China. The upper fossiliferous layer (ca. 3 m, upper K. disparilis subzone) yields a diverse brachiopod fauna, including at least 15 genera and displaying the highest diversity of brachiopods ever recorded in a single fossiliferous bed from the upper Givetian of South China.

国家自然科学基金(41772015)资助