title: Phylogenetic position of the marine ciliate, Cardiostomatella vermiforme (Kahl, 1928) Corliss, 1960 inferred from the complete SSrRNA gene sequence, with establishment of a new order Loxocephalida n. ord. (Ciliophora, Oligohymenophorea).
abstract: The small subunit rRNA (SSrRNA) gene was sequenced for Cardiostomatella vermiforme, a large marine ciliate the systematic position of which is uncertain but which has been regarded as a scuticociliate for about forty years. The present work indicates that this organism, together with a closely related species, Dexiotrichides pangi, always form a separate assemblage as a sister group to the scuticociliates sensu stricto. The fact that the clade comprising Cardiostomatella and Dexiotrichides branches between the typical scuticociliates and Hymenostomatia, and shares a series of morphological and morphogenetical characters with both, supports the conclusion that it belongs to an intermediate group between the two. We suggest that this group represents a new order, Loxocephalida n. ord. within the subclass Scuticociliatia, which possibly contains all taxa within the families Loxocephalidae and Cinetochilidae and with Loxocephalidae as the type family.
authors.affiliation: Laboratory of Protozoology, KLM, Ocean University of China, Qingdao 266003, PR China.
authors.forename: Lifang
authors.initials: L
authors.lastname: Li
authors.forename: Weibo
authors.initials: W
authors.lastname: Song
authors.forename: Alan
authors.initials: A
authors.lastname: Warren
authors.forename: Yangang
authors.initials: Y
authors.lastname: Wang
authors.forename: Honggang
authors.initials: H
authors.lastname: Ma
authors.forename: Xiaozhong
authors.initials: X
authors.lastname: Hu
authors.forename: Zigui
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000818:Animals; D001483:Base Sequence; D001499:Bayes Theorem; D016054:DNA, Protozoan / Q000737:chemistry; D004275:DNA, Ribosomal / Q000737:chemistry; D020459:Genes, rRNA / Q000235:genetics*; D008969:Molecular Sequence Data; D016802:Oligohymenophorea / Q000145:classification* / Q000235:genetics* / Q000648:ultrastructure; D010802:Phylogeny; D016053:RNA, Protozoan / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D016415:Sequence Alignment; D013045:Species Specificity
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D016053:RNA, Protozoan; D012335:RNA, Ribosomal