Centrohelea Kühn 1926

 

Diagnosis: Non-flagellate heliozoa with axopodial axonemes; nucleus eccentric; centrosome central; two types of siliceous scales present ancestrally (flat inner tangential plate scales and elongated, usually pointed, outer radial spine scales), but outer scales or both scale layers secondarily lost in several derived lineages.

 

Included families:

     
1

Periplast composed of siliceous scales

2

-

Periplast without siliceous elements

5
     
2

Periplast with tangential rod-shaped spicules or plates

Raphidiophryidae
-

Periplast wit tangential plates and radial spicules

3
     
3

Radial spicules with centrally attached basal plate

Acanthocystidae
-

Radial spines without such a plate

4
     
4

Radial spines with winglike structures

Pterocystidae
-

Radial spines with eccentrically attached basal plate

Choanocystidae
     
5

18S rRNA short

Heterophryidae
-

18S rRNA markedly longer

Marophryidae