Kelly-Borges M, Pomponi S A
Division of Biomedical Marine Research, Harbor Branch Oceanographic Institution, Fort Pierce, FL 34946.
Mol Mar Biol Biotechnol. 1994 Apr;3(2):87-103.
Traditionally, lithistid sponges have been combined within one order linked by the common possession of an interlocking siliceous desma skeleton. However, molecular data, morphology, and paleontology confirm recent hypothesis of polyphyly for this enigmatic group of sponges. Parsimony and neighbor-joining analysis of partial 18S rDNA sequences derived from amplified genomic rDNA of lithistids and other demosponges suggest that tetracladinid and dicranocladinid lithistids are monophyletic and closely related to choristid demosponges. Rhizomorinid families, in contrast, are indicated as being polyphyletic, with a diversity of points of origin within the tetractinomorph and the ceractinomorph poriferan subclasses. These arrangements are discussed in light of several hypotheses of demosponge evolution.
传统上，石海绵被归为一个目，其共同特征是拥有相互连锁的硅质骨针骨架。然而，分子数据、形态学和古生物学证实了关于这一神秘海绵类群多系起源的最新假说。对从石海绵和其他寻常海绵纲海绵的扩增基因组rDNA中获得的部分18S rDNA序列进行简约分析和邻接法分析表明，四枝骨针石海绵科和双枝骨针石海绵科的石海绵是单系的，并且与离海绵目寻常海绵关系密切。相比之下，根绵科被认为是多系的，在四放海绵亚纲和角骨海绵亚纲内有多种起源点。根据寻常海绵进化的几种假说对这些分类进行了讨论。
