Concise hierarchy

(Kingdom) Animalia - (Phylum) Arthropoda - (Class) Arachnida - (Order) Trombidiformes

Current position

Protohydrachnidia ([unranked]) Witte & Olomski, 1991

Ref: M. Dabert et al., 2016: 88.

Alternative positions

Anystina (Infraorder) van der Hammen, 1972	Ref: O. Bánki et al., 2023: 17 Aug 2023; CoL(17 Aug 2023).
Hydracarnidiae (Subcohort) Dunlop, Penney & Jekel, 2010, orth. inval.	Ref: J.A. Dunlop et al., 2023: 88.
Hydrachnidia ([unranked]) Krantz, 1978	Ref: H. Smit, 2020: 55.
Hydrachnidiae (Subcohort)	Ref: G.W. Krantz & D.E. Walter, 2009: 99.
Parasitengona (Hyporder) Oudemans, 1909	Ref: Z.-Q. Zhang et al., 2011: 131.
Parasitengona (Suborder) Oudemans, 1909	Ref: J. Hallan, [2003]: 01 Sep 2005.

Historical positions

Hydracarnidiae (Subcohort) Dunlop, Penney & Jekel, 2010, orth. inval.	Ref: J.A. Dunlop et al., 2023: 88.
Hydrachnidia ([unranked]) Krantz, 1978	Ref: H. Smit, 2020: 11, 55.
Parasitengona (Hyporder) Oudemans, 1909	Ref: Z.-Q. Zhang et al., 2011: 131.
Hydrachnidiae (Subcohort)	Ref: G.W. Krantz & D.E. Walter, 2009: 99.

Number of Subtaxa

2025	Available in Systema Naturae 2000	4f;16g;24s
1989-present	Systema Naturae 2000: 25 Aug 2024	[4f;16g; †0s]
2023	J.A. Dunlop et al.: 89	[4f; †0s]
2020	H. Smit: 11	[4f;16g]
2011	Z.-Q. Zhang et al.: 131	4f
[2003]	J. Hallan: 01 Sep 2005	[4f]