The organization of the lophophore and the digestive system are recognized as two of the diagnostic characters in the definition of higher brachiopod taxa, and hence play a major role in their phylogenetic analysis, their structure, however, is very rarely fossilized. Here we describe and interpret specimens of the brachiopod Lingulellotreta malongensis, from the Lower Cambrian Chengjiang Lagerstätte ( South China ), one of the earliest known taxa of the Lingulellotretidae, in which lophophores and intact, U-shaped digestive tracts are extraordinarily well-preserved. The lophophore, with clearly preserved tentacles, corresponds to an early spirolophe developmental stage. The digestive tract consists of a mouth, esophagus, distended stomach, intestine and an anterior anus, and differs from that of the Chengjiang obolid Lingulella chengjiangensis by the presence of the dilated stomach and by the absence of a looped intestine as in Lingula. In addition, the relative sizes of the mantle and visceral cavities of Lingulellotreta malongensis also are described. These fossils demonstrate that by the Atdabanian brachiopods had already possessed advanced features, and suggest that a lophophore and a U-shaped intestine with an anterior anus are brachiopod plesiomorphies.

Key words: Linguloidea, lophophore, digestive tract, Lower Cambrian, Chengjiang Lagerstätte, China.

Zhifei Zhang [zhangelle@sina.com.cn], Jian Han [hanjianelle@263.net], Xingliang Zhang [Xlzhang@pub.xaonline.com], and Jianni Liu [liujianni@263.net], Early Life Institute and Key Laboratory for Continental Dynamics of the Ministry Education, Northwest University, Xi’an, 710069, China; Degan Shu [elidgshu@nwu.edu.cn], Early Life Institute and Department of Geology, Northwest University, Xi’an, 710069, China; School of Earth Sciences and Resources, China University of Geosciences (Beijing), 100083, China.