摘要
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。
Soft bodied worms have been collected recently from the middle part of the Kaili Formation (Middle Cambrian), increasing the known diversity of the Kaili Biota. In addition to the five genera discussed in the present paper—? ttoia Walcott, 1911, Palaeoscolex Whittard, 1953, Cricocosmia? Hou et Sun, 1988, Selkirkia Walcott, 1911 and Maotainshania Sun et Hou, 1987——the Kaili Biota also contains fossil worms that have not yet been identified. According to recent classifications, worms are not a true clade, but a polyphyletic group of soft bodied organisms collectively showing a variety of body plans. Fossil worms consist mainly of coelomate phyla including Annelida, Echiuroidea, Sipunculoidea, Priapulida, Phoronida, Chaetognatha and phyla lacking a coelum or having a pseudocoelum as Nemertinea, Platyhelminthes and Aschelminthes. Because fossil worms tend to be poorly preserved, classification of these organisms is difficult. Although soft bodied fossil worms continue to be collected and studied (e.g. Walcott, 1911; Resser, 1939; Robison, 1969; Sun and Hou, 1987; Hou and Sun, 1988; Hou and Bergstrm, 1994; Conway Morris and Robison, 1986,1988;Lin,1995),their classification remains difficult, and relationships above the class level are fluid. For example, whereas Chen et al. (1996) assigned Palaeoscolex to priapulids, Hou and Bergstrm (1994) concluded that Palaeoscolex lacked a true coelom and assigned it to the pseudocoelomate group Nematomorpha (Hou and Bergstrm, 1994). The present paper describes five fossil worm genera having a proboscis and an annulated trunk. In one of these genera, Selkirkia, the soft body was encased in a tube (Walcott,1911; Conway Morris, 1977). The authors here accepted more recent opinion on position of the these worms and considered them as priapulid worms, because of the similar proboscises (Conway Morris, 1997). Because fossil worms are abundant in the Kaili biota, the Kaili biota is a typical Burgess Shale type biota.
出处
《古生物学报》
CAS
CSCD
北大核心
1999年第S1期79-87,180-181,共11页
Acta Palaeontologica Sinica
基金
国家自然科学基金!(49772 0 85 )
攀登专项!(95 专 0 1)
贵州省科学基金资助成果
中国科学院"百人计划"成果之一
