Gephyrocapsa oceanica color.jpg
The coccolithophore Gephyrocapsa oceanica
Scientific classification edit
Okamoto et al., 2009
  • CCTH
  • Eukaryomonadae

The cryptomonads-haptophytes assemblage is a proposed monophyletic grouping[1] of unicellular eukaryotes that are not included in the general suffix referring to life);[2] CCTH (standing for Cryptophyta, Centrohelida, Telonemia and Haptophyta);[3] and "Eukaryomonadae".[4]

As of February 2012, it is unclear whether this group is monophyletic or not; results of phylogenetic studies are "often dependent on the selection of taxa and gene data set".[3] Two 2012 studies produced opposite results.[3][5]


In the past, heterokonts, haptophytes, and cryptomonads have sometimes been grouped together in a group known as chromists.[6] Though the heterokonts are now split out, Cryptophyta and Haptophyta are considered in some studies to be closely related[7][8] (and are sometimes simply referred to as the "Cryptophyta+Haptophyta" group).[9] A 2009 paper suggested that the Telonemia and centrohelids may form a clade with the cryptophytes and haptophytes.[10] The picobiliphytes may belong in this group but are too poorly known to be classified with confidence.[2]

Several recent studies have concluded that Haptophyta and Cryptophyta do not form a monophyletic group.[11] The former are a sister group to the SAR group, the latter cluster with the Archaeplastida (plants in the broad sense).[5] As of February 2012, it remains unclear whether the Hacrobia forms a monophyletic group.[3]

Another study[12] suggested the following arrangement: centrohelids are related to haptophytes and form the clade Haptista; Haptista is the sister group to SAR; Cryptista are related to Archaeplastida; and Haptista + SAR is the sister clade to Cryptista + Archaeplastida.

Other Languages
العربية: هكروبيات
català: Hacrobi
español: Hacrobia
فارسی: هکروبیا
français: Hacrobia
galego: Hacrobios
한국어: 하크로비아
日本語: ハクロビア
português: Hacrobia