16 – 28 % of the thymines
||Soyer-Gobillard MO, Dolan MF. Chromosomes of Protists: The crucible of evolution. Int Microbiol. 2015 Dec18(4):209-16. doi: 10.2436/20.1501.01.252 p.212 right column top paragraphPubMed ID27611673
|| Herzog M, Soyer MO (1983) The native structure of dinoflagellate chromosomes and their stabilization by Ca2+ and Mg2+ cations. Eur J Cell Biol 30: 3  Rae PM. 5-Hydroxymethyluracil in the DNA of a dinoflagellate. Proc Natl Acad Sci U S A. 1973 Apr70(4):1141-5.PubMed ID6682763, 4515611
||P.212 left column bottom paragraph: "At the molecular level, dinoflagellate DNA is peculiar in terms of density and thermal denaturation due to the presence
of an unusual base, 5-hydroxymethyluracil (HOMedU), which
replaces 16–28% of the thymines [primary sources]. The occurrence of this pyrimidine base replacing thymine was described for the
first time in a bacteriophage [ref 17]."