Homalorhagida

Pycnophyes calmani, from here.

Belongs within: Ecdysozoa.

The Homalorhagida are a group of marine kinorhynchs distinguished by their triangular cross-section.

Characters (from Higgins 1986): 6-8 neck plates; distinctly triangular in cross-section; spines reduced.

Homalorhagida [Homalorhagae]
    |--Neocentrophyes Higgins 1969 [Neocentrophyidae] H86
    |    |--N. intermedius Higgins 1969 H86
    |    `--N. satyai Higgins 1969 H86
    `--Pycnophyidae H86
         |--Kinorhynchus Sheremetevskij 1974 H86
         |    |--K. anomalus Lang 1953 H86
         |    |--K. apotomus Higgins 1983 H86
         |    |--K. belizensis Higgins 1983 H86
         |    |--K. cataphractus Higgins 1961 H86
         |    |--K. deirophorus Higgins 1983 H86
         |    |--K. distentus Higgins 1983 H86
         |    |--K. erismatus Higgins 1983 H86
         |    |--K. fimbriatus Higgins 1982 H86
         |    |--K. giganteus (Zelinka 1908) H86
         |    |--K. ilyocryptus Higgins 1961 H86
         |    |--K. langi (Higgins 1964) H86
         |    |--K. mainensis (Blake 1930) H86
         |    |--K. paraneapolitanus Sheremetevskij 1974 H86
         |    |--K. phyllotropis Brown & Higgins 1983 H86
         |    |--K. spinosus (Lang 1949) H86
         |    |--K. stenopygus Higgins 1983 H86
         |    `--K. trisetosus Higgins 1983 H86
         `--Pycnophyes Zelinka 1907 H86
              |--P. beaufortensis Higins 1964 H86
              |--P. calmani Southern 1914 H86
              |--P. carinatus Zelinka 1928 H86
              |--P. chiliensis Lang 1953 H86
              |--P. communis Zelinka 1908 H86
              |--P. corrugatus Higgins 1983 H86
              |--P. dentatus (Reinhard 1881) H86
              |--P. echinoderoides Zelinka 1928 H86
              |--P. ecphantor Higgins 1983 H86
              |--P. egyptensis Higgins 1966 H86
              |--P. emarginatus Higgins 1983 H86
              |--P. flagellatus H86
              |--P. flaveolatus Zelinka 1928 H86
              |--P. frequens Blake 1930 H86
              |--P. iniorhaptus Higins 1983 H86
              |--P. kielensis Zelinka 1928 H86
              |--P. longicornis Higgins 1983 H86
              |--P. maximus Reimer 1963 H86
              |--P. odhneri Lang 1953 H86
              |--P. ponticus (Reinhard 1881) H86
              |--P. robustus Zelinka 1928 H86
              |--P. rugosus Zelinka 1928 H86
              |--P. sanjuanensis Higgins 1961 H86
              |--P. sculptus Lang 1949 H86
              `--P. zelinkaei Southern 1914 H86

*Type species of generic name indicated

REFERENCES

[H86] Higgins, R. P. 1986. Kinorhyncha. In Stygofauna Mundi: A Faunistic, Distributional, and Ecological Synthesis of the World Fauna inhabiting Subterranean Waters (including the Marine Interstitial) (L. Botosaneanu, ed.) pp. 110-118. E. J. Brill / Dr. W. Backhuys: Leiden.

Cyclorhagida

Images of Campyloderes cf. vanhoeffeni from Neuhaus & Sørensen (2012). Original caption: "SEM (A–C, F–H) and DIC images (D, E, J, K) of male (C, J) and female (A, B, D–H, K) Campyloderes cf. vanhoeffeni from the Galápagos area (A, E), Antarctica (B, H) and the Faroe Islands (C, D, F, G, J, K). (A, B) Habitus from left side (A) and ventral side (B). Arrow heads mark sensory spots. (C) Mouth cone in surface view, individual outer oral styles absent. (D, E) Optical section of mouth cone of specimens ZMUC KIN-87 (D) and ZMB 5967i (E). Inner oral styles recognizable in specimen from Galápagos area (E) but not in Faroe specimen (D). Pharynx with alternating circular and radial muscle cells in (E). (F, G). Tip of mouth cone (F) and detail of fused outer oral styles (G). (H) Frontal view of placids. (J, K) Head and placids of specimens ZMUC KIN-95 (J) and KIN-94 (K) in ventral (J) and dorsal view (K). Scale bar in A and B 200 μm, in C and H 20 μm, in D 30 μm (valid for D, E), in F 5 μm, in G 2 μm, in J 30 μm (valid for J, K)."

Belongs within: Ecdysozoa.
Contains: Echinoderes.

The Cyclorhagida is the larger of the two major groups of kinorhynchs, small worm-like animals found mostly in marine sediments.

Characters (from Higgins 1986): 14-16 neck plates; generally round to oval-triangular; usually with numerous lateral middorsal and occasionally midterminal spines.

Cyclorhagida
    |--Cateria Gerlach 1956 [Cateriidae, Cryptorhagae] H86
    |    |--C. gerlachi Higgins 1968 H86
    |    |--C. styx Gerlach 1956 H86
    |    `--C. submersa Gerlach 1969 H86
    |--Semnoderidae [Conchorhagae] H86
    |    |--Sphenoderes Higgins 1969 H86
    |    |    `--S. indicus Higgins 1969 H86
    |    `--Semnoderes Zelinka 1907 H86
    |         |--S. armiger Zelinka 1928 H86
    |         |--S. pacificus Higgins 1967 H86
    |         `--S. ponticus Băcescu & Băcescu 1956 H86
    `--Cyclorhagae H86
         |--Echinoderes H86
         |--Condyloderes Higgins 1969 [Condyloderidae] H86
         |    |--C. multispinosus (McIntyre 1962) H86
         |    `--C. paradoxus Higgins 1969 H86
         `--Centroderidae H86
              |--Centroderes Zelinka 1896 H86
              |    |--C. eisigii Zelinka 1928 H86
              |    `--C. spinosus (Reinhard 1881) H86
              `--Campyloderes Zelinka 1913 H86
                   |--C. adherens Nyholm 1947 H86
                   |--C. macquariae Johnston 1938 H86
                   `--C. vanhoeffeni Zelinka 1913 H86

*Type species of generic name indicated

REFERENCES

[H86] Higgins, R. P. 1986. Kinorhyncha. In Stygofauna Mundi: A Faunistic, Distributional, and Ecological Synthesis of the World Fauna inhabiting Subterranean Waters (including the Marine Interstitial) (L. Botosaneanu, ed.) pp. 110-118. E. J. Brill / Dr. W. Backhuys: Leiden.

Neuhaus, B., & M. V. Sørensen. In press, 2012. Populations of Campyloderes sp. (Kinorhyncha, Cyclorhagida): one global species with significant morphological variation? Zoologischer Anzeiger.