贵州中寒武世凯里生物群中的蠕形动物化石

描述了凯里生物群中的蠕形动物Ottoia ,Maotianshania ,Palaeoscolex ,Circocosmia?及Selkirkia。这些软躯体的蠕虫化石在凯里生物群中都是首次发现。其中Ottoia也发现于布尔吉斯页岩生物群 ,Maotianshania ,Circocosmia ?则见于澄江生物群 ,而Palaeoscolex则从澄江生物群至布尔吉斯页岩生物群中都有保存 ,这是凯里生物群处于承前启后位置的又一证据。蠕动动物的发现 ,增加了凯里生物群软躯体化石内容 ,反映了凯里生物群是典型的布尔吉斯页岩生物群。

A New Platy-armored Worm from the Early Cambrian Chengjiang Lagerstatte,South China

The Lower Cambrian Chengjiang Lagerstatte provides a good window to explorethe origin and radiation of early bilaterians. Here we describe a netted sclerite-bearing wormTabelliscolex hexagonus gen. et sp. nov., and tentatively assign it to palaeoscolecidans ofpriapulids. The cuticle of the animal is covered with two kinds of platy sclerites which areconstructed by hexagonally arranged tubercles Similar structures of the sclerites can be seen onsome Cambrian palaeoscolecidans and lobopods, so, this new species is critical for understanding therelationships between lobopods and palaeoscolecidans.

云南晋宁梅树村剖面古蠕虫再研究

对云南晋宁梅树村剖面下寒武统黑林铺组(原筇竹寺组)玉案山段的蠕形动物化石Sabellidites yunnanensis Luo et Zhang,S.badaowanensis Luo et Zhang的模式标本进行重新研究,通过虫体躯干表皮骨板的排列方式与产于同一剖面相同层位的古蠕虫Mafangscolex sinensis Hu 2005以及Palaeoscolex sinensis Hou et Sun躯干体环上骨板排列方式进行对比,认为前3个种躯干表面骨板的排列方式完全相同,即每一体环均有5横排骨板,但与中华古蠕虫(Palaeoscolex sinensis)每一体环只有4横排大骨板的特征不相吻合。建议采用Mafangscolex yunnanensis作为前3者的属种名称,并以最早发表的Sabellidites yunnanensis Luo et Zhang作为该属的模式种。

Priapulid worms from the Cambrian of China shed light on reproduction in early animals

In the recent years,exceptional fossil sites have revealed astonishing details on the anatomy,lifestyles and behaviour of Cambrian animals but surprisingly,very little is known about one of their most vital features,reproduction.We describe here in situ eggs(clusters of 3 to 30 oocytes)in the tube-dwelling priapulid worm Paraselkirkia sinica from the Cambrian Stage 3 Xiaoshiba Lagerstätte(ca.514 Ma,South China).These oocytes were accommodated within paired tubular ovaries located in the posterior half of the primary body cavity as in modern meiobenthic priapulid worms,thus indicating that the general organization of female tubular gonads in priapulid worms has remained virtually unchanged for half a billion years.Our findings provide for the first time,key information on the reproductive organs and strategies of early ecdysozoans,a huge animal clade that dominated Cambrian marine ecosystems and accounts for a large part of today’s biodiversity(e.g.arthropods).Moreover,we also emphasize the critical role of ecology on the reproductive strategies and lifestyles of both modern and Cambrian worms.