A new exceptionally preserved Cambrian priapulid from the Chengjiang Lagerstätte

A fossil priapulid, Eximipriapulus globocaudatus new genus new species, is described from the Cambrian Chengjiang Lagerstätte of Yunnan, China. The exceptional preservation of the animal reveals morphological details that allow direct comparison with extant priapulids. The body is divisible into a partially eversible pharynx, a smooth collar, a scalid-bearing introvert, a neck with triangular scalids, an unsegmented trunk with annulations, and a distinctly expanded terminal region. Several specialized regions of the alimentary canal are recognized: a pharynx (lined by cuticle and bearing teeth), esophagus, midgut, hindgut, and a terminal anus. The sample includes a putative juvenile. The animal is inferred to have been an active burrower using a double-anchor strategy, practicing both deposit feeding and carnivory. Inclusion of Eximipriapulus in the most recent character matrix for cladistic analysis of fossil and Recent priapulids resolves the new genus within the priapulid crown group...

本研究记述了产自中国云南寒武纪澄江特异埋藏化石群（Chengjiang Lagerstätte）的曳鳃动物新属新种Eximipriapulus globocaudatus。该标本保存异常完好，其形态细节可与现生曳鳃动物直接比对。其躯体可划分为可部分外翻的咽、光滑领区、具吻棘的翻吻、着生三角形吻棘的颈段、带有环纹且不分节的躯干，以及显著膨大的末端区域。本次研究识别出消化道的多个特化区段：由角质层内衬并具齿的咽、食道、中肠、后肠与末端肛门。标本中还包含一件疑似幼体的个体。据推测，该动物采用双锚定策略营主动掘穴生活，兼具沉积食性与肉食性两种取食方式。将Eximipriapulus纳入用于化石与现生曳鳃动物支序分类分析的最新特征矩阵后，系统发育分析结果显示该新属隶属于曳鳃动物冠群。