云南寒武纪早期澄江生物群中原始海绵新种:囊形似斜纹海绵Paradiagoniella marsupiata sp.nov.

New Protospongia from the Early Cambrian Chengjiang Biota:Paradiagon iella Marsupiata Sp.nov

报道澄江生物群似斜纹海绵属Paradiagoniella的新种:囊形似斜纹海绵P.marsupiatasp.nov.,以及部分离散保存的十字骨针、六射针.新种具有似斜纹海绵属的基本特征:体壁薄;由排列不规则、分级的十字骨针为基底构成骨骼;除十字骨针外,还穿插排列有五射针、弯弓形和针形双尖单轴针等.然而与模式种不同,新种十字骨针分级不明显,且与本属已知种P.magna和P.xiaolantianensis在外形、骨针组成、最大十字骨针射长比等方面,都存在明显差异.新材料的发现增加了寒武纪早期原始海绵物种多样性,为研究海绵动物早期起源演化提供了新信息.

The new species of Paradiagoniella collected from the Chengjiang biota,Paradiagoniella.marsupiata sp.nov,are reported here.Similar to P.magna(type species)and P.xiaolantianensis,they are thin-walled sponge with dense mesh of stauractines,minor amount of oxeas(straight or curveddiactines)to form their main skeleton and rare hexactine or pentactine present in them.The new species have stauractines not so obviously ranked as type species,and are quite different from the known P.magna and P.xiaolantianensis in the form of body,the composition of spicules and the long shot ratio of the largest stauractine.The discovery makes protospongiid sponges of early Cambrian period more diversified and provide new information for understanding the birth and evolution of spongia.