Type species: Kyphocalanus atlanticus Markhaseva & Schulz, 2009. 1 sp + 4 without denomitation.
For Markhaseva & Schulz (2009, p.23-24) synapomorphies (commun possession of derived homologous characters ) for the genus Kyphocalanus are the presence of a knife handle-like basal part of the prosximal seta on the mandibular basis and the maxillule distal basal endite and endopod separate and the distal basal endite bearing 1 seta only (vs. 2-6 setae in other ‘Bradfordians’).
In addition to the characters of the family, the new genus differs from the majority of other ‘Bradfordian’ families/genera by the following derived characters :
1- A2 basis without setae, shared with tharybid genus Brodskius Markhaseva & Ferrari (2005), contrasting the presence of 1-2 setae in other ‘Bradfordians’.
2- A2 endopod segment 1 without setae, shared with Pseudophaenna Sars (1902) (genus of unclear familial position) and some species of the tharybid genus Undinella Sars (1900), and contrary to 1-2 setae in other ‘Bradfordians’.
3- A2 endopod segment 2 with fewer than 10 setae, shared with Pseudophaenna, but this segment with 11-15 setae in other ‘Bradfordians’.
4- Maximmule proximal basal endite without setae, shared with Bradfordiella Andronov (2007) (genus of unclear familial position), in contrast to the presence of 2-5 setae in other ‘Bradfordians’.
5- Maxilla proximal praecoxal endite with 2 setae, shared with Rostrocalanus and some species of Bradfordiella, but with 3-5 setae in other ‘Bradfordians’.
6- Maxilla distal praecoxal endite and proximal coxal endite with 2 setae each, shared with some species of Bradfordiella, and contrary to 3 setae in other ‘Bradfordians’.
7- Maxilla distal coxal endite with 2 setae, shared with Phaenna Claus (1863) (Phaennidae), but with 3 setae in other ‘Bradfordians’.
8- Maxilla proximal basal endite with 1 setal element, shared with Bradfordiella, but with 3-4 setal elements in other ‘Bradfordians’.
9- 1 seta on Maxilliped coxal endite, shared with some species of Undinella and Bradfordiella, in contrast to presence of 2 or 3 setae in other ‘Bradfordian genera’.
The similar derived armament of some oral limbs of Kyphocalanus and Bradfordiella is assumed to have arisen in a parallel development and independently, and thus both genera are not considered to be closely related. This is corroborated by apomorphies not shared by Bradfordiella : 1- praecoxal arthrite of Mx1 with 3 setae (vs. 9 in Bradfordiella ; 2- distal coxal endite of Mx2 with 2 setae (vs. 3 setae inBradfordiella ; 3- Mx2 distal basal endite plus endopod with 8 very long and thick, worm-like sensory setae, longer than all sclerotized setae of Mx2 (vs. only 6 short sensory setae of unclear morphology in Bradfordiella.
In addition, Kyphocalanus does not share apomorphies of Bradfordiella : 1- A1 of only 18 segments (vs. 24 in Kyphocalanus) ; 2- Mandibular basis lacking setae (vs. 2 setae in Kyphocalanus) ; 3- Mx1 with coxal and basal endites reduced (vs. these enditese well developed in Kyphocalanus) ; 4- Mxp praecoxal endites of syncoxa lacking setae (with 1, 2, 0 setae in Kyphocalanus).

Diagnosis from Markhaseva & Schulz (2009, p.23) :
Female :
- Cephalon in lateral view bent anteriorly.
- Rostrum as two short, prong-like points.
- Cephalosome and pediger somite 1, pedigers 4 and 5 separate.
- Urosome very short, of 4 somites, genital double-somite being the largest.
- A1 shorter than prosome.
- A2 : basis, endopodal segment 1 and exopodal segment 1 without setae ; endopodal segment 2 with 3 or 4 setae on inner lobe ; exopodal segment 2 with 1 short seta.
- Md gnathobase long and slender, with narrow cutting edge ; basis with 2 setae, proximal seta with conspicuous thickening at 1/3 length ; endopodal segment 1 without setae, segment 2 with 9 setae ; exopod 5-segmented with 1, 1, 1, 1, and 1 setae.
- Praecoxal endite of Mx1 with 3 slender setae ; proximal basal endite without setae ; distal basal endite with 1 seta and separate from endopod bearing 5 setae.
- Mx2 praecoxal and coxal endites usually with 2 slender setae each ; basal endite with 1 strong spine ; endopod with 8 long and thick worm-like sensory setae.
- Praecoxal lobes of Mxp syncoxa with 1 thin, slender and comparably short worm-like sensory seta on proximal lobe and 2 thick and long worm-like setae on medial lobe ; distal lobe without seta, setal formula 1, 2, 0 ; coxal endite with 1 slender seta.
- P4 coxa, basis, endopod, and exopod segment 1 with posterior surface spinulation or not.
-P5 3-segmented, exopod with 2 unequal spines (1 shorter, terminal and 1 longer, inner and subterminal spine).
Male unknown