Rhombognathus

Belongs within: Halacaridae.

Rhombognathus is a genus of halacarid mites with minute palpi and two setae each on the ocular plates (Luxton 1990). Smooth claws lacking an accessory process are found in R. caribaeus and R. pseudolionyx (Bartsch 2007).

Characters (from Luxton 1990): Dorsal plates well developed; ventral plates often fused; ocular plates each with two setae; genital opening of female ventral; legs bidactylous; sclerite between end of leg and base of claws rod-like.

<==Rhombognathus Trouessart 1888B07 [incl. Aletes Lohmann 1889 nec Rafinesque 1815 nec Carpenter 1857 nec Chapuis 1874N47]
    |--*R. notops (Gosse 1855) (see below for synonymy)N47
    |--R. apsteini Lohmann 1907N47
    |--R. biscutatus Bartsch 1993H98
    |--R. caribaeus Bartsch 2007B07
    |--R. foveolatus Bartsch 1993H98
    |--R. fractus Bartsch 1979L90
    |--R. gressitti Newell 1967 [incl. R. magnirostris var. lionyx Trouessart 1914]SL71
    |--R. intermedius Schulz 1933N47
    |--R. lacunosus Bartsch 1979L90
    |--R. latens Bartsch 1993H98
    |--R. latibulus Bartsch 1993H98
    |--R. lepidus Bartsch 1993H98
    |--R. leurodactylusWL09
    |--R. levigatoidesDPD16
    |--R. magnirostris Trouessart 1889B07 [=R. magnipalpus (l. c.)N47]
    |    |--R. m. magnirostrisN47
    |    |--R. m. plumifer Trouessart 1889N47
    |    `--R. m. praegracilis Viets 1939N47
    |--R. marginalis Bartsch 1993H98
    |--R. novaezelandicus Bartsch 1986L90
    |--R. parvulus Viets 1939N47
    |--R. pectinatus Viets 1936B07
    |--R. peltatus Viets 1939B07
    |--R. placidus Bartsch 1993H98
    |--R. psammophilus Bartsch 1993H98
    |--R. pseudolionyx Newell & André 1959B07
    |--R. reticulatusWL09
    |--R. scutulatus Bartsch 1983H98
    |--R. sphaerorhynchus Police 1909N47
    |--R. spinipes Viets 1933N47
    |--R. thalassinus Bartsch 1993H98
    |--R. uniscutatus Viets 1939N47
    `--R. validipes Bartsch 2000B07

*Rhombognathus notops (Gosse 1855) [=Pachygnathus notops, *Aletes notops; incl. A. gracilis Lohmann 1889, Rhombognathus longirostris Trouessart 1888]^N47

*Type species of generic name indicated

References

[B07] Bartsch, I. 2007. Rhombognathus from the Caribbean area, with the description of a new species (Arachnida, Acari, Halacaridae). Senckenbergiana Biologica 87 (1): 17–22.

[DPD16] Dabert, M., H. Proctor & J. Dabert. 2016. Higher-level molecular phylogeny of the water mites (Acariformes: Prostigmata: Parasitengonina: Hydrachnidiae). Molecular Phylogenetics and Evolution 101: 75–90.

[H98] Halliday, R. B. 1998. Mites of Australia: A checklist and bibliography. CSIRO Publishing: Collingwood.

[L90] Luxton, M. 1990. The marine littoral mites of the New Zealand region. Journal of the Royal Society of New Zealand 20 (4): 367–418.

[N47] Newell, I. M. 1947. A systematic and ecological study of the Halacaridae of eastern North America. Bulletin of the Bingham Oceanographic Collection 10 (3): 1–232.

[SL71] Spain, A. V., & M. Luxton. 1971. Catalog and bibliography of the Acari of the New Zealand subregion. Pacific Insects Monograph 25: 179–226.

[WL09] Walter, D. E., E. E. Lindquist, I. M. Smith, D. R. Cook & G. W. Krantz. 2009. Order Trombidiformes. In: Krantz, G. W., & D. E. Walter (eds) A Manual of Acarology 3^rd ed. pp. 233–420. Texas Tech University Press.