Haptista

Haptista is a group of protists made up of centrohelids and haptophytes. Phylogenomic studies indicate that Haptista is likely closely related to the TSAR supergroup. It is thus one of the earliest diverging Diaphoretickes.

The centrohelids or centroheliozoa are a group of heliozoan protists, single-celled eukaryotes with stiff radiating arms (known as axopodia) supported by microtubules and bearing extrusomes (known as kinetocysts). Their cells are spherical, ranging from 3 to 150 μm. Unlike other heliozoa, centrohelids lack flagella, have flat ribbon-shaped mitochondrial cristae, and arrange their microtubules in hexagons or triangles. Their microtubule-generating organelle, the centroplast, has a unique shape with a central trilamellar disc surrounded by two hemispherical caps. Some are naked or covered in a m