Crinoids of the stalked family Hyocrinidae (Echinodermata) collected by the USNS Eltanin in the Southern Ocean Author Roux, Michel text Zootaxa 2015 3990 3 381 409 journal article 10.11646/zootaxa.3990.3.4 471bf6e4-a502-401c-bee1-3535ac5305e4 1175-5326 243049 08B0220E-DC57-439C-A5B7-706B2202B1A1 Genus Thalassocrinus A.H. Clark, 1911 Type species of the genus: Thalassocrinus pontifer A.H. Clark, 1911 . Synonymy: A.H. Clark, 1911 : 174; 1915: 160; Gislén, 1939 : 13; Roux, 1980: 40–42; Mironov & Sorokina, 1998 : 34; Roux, 2002: 174; Roux & Lambert, 2011 : 48, 51. Remarks. Roux & Lambert (2011) suspected Thalassocrinus to be a polyphyletic genus. They pointed out significant differences in anal sac features that suggested close affinities between (1) T. pontifer and Hyocrinus bethellianus Thomson, 1876 , (2) T. alvinae Roux, 2002 , and T. clausus Mironov & Sorokina, 1998 , and (3) T. mironovi Roux, 2002 , and Laubiericrinus pentagonalis Roux, 2004 . Molecular phylogeny ( Roux et al. 2013 ) confirmed that T. pontifer and H. bethellianus are closely related. DNA sequences from the four other species need to be added to get a better understanding of the interrelationships between these species. The genus Thalassocrinus sensu lato is therefore provisionally maintained.