Order SPUMELLARIA Ehrenberg, 1876

Phylogenetic molecular lineage I (Sandin et al. 2021).

DIAGNOSIS. — No common morphological characters have been recognized yet.

REMARKS

The lineage I includes the superfamilies Hexacromyoidea (including Clades A to C), Spongosphaeroidea (including Clade D), Lithocyclioidea (including Clade E1)and Spongodiscoidea (including Clades E2 and E3). This Lineage consists of Clades A, B, C, D and E. The group of Clades D and E is independent from other clades with 100% PhyML bootstrap values, with 10 000 replicates (BS) and>0.99 posterior probabilities (PP) in 18SrDNA. A group of Clades A, B and C is separable from the group of Clades D and E, but their clustering is not stable as of yet. Hexacromyum (originally Hexacontium) was clustered into both Clades A and B so that these two clades did not have to be grouped as a single superfamily in Hexacromyidae . Hollandosphaera was correctly grouped in a single Clade B and thus, Hollandosphaeridae was applicable to this Clade. Clade E exclusively includes Spongosphaera in order to assign it as Spongosphaeridae . Clade E1 includes Didymocyrtis and Spongolivella (originally Cypassis), Clade E2 includes Spongocyclia and Schizodiscus, and Clade E3 includes Dictyocoryne, Spongodiscus, Spongaster and Tricranastrum (originally Myelastrum and Triastrum). Almost all branches within Cluster E have a very low support in 18SrDNA; however, the Clade E fits well with the superfamily Spongodiscoidea . As Lithocyclioidea is considered an ancestor of Didymocyrtis, this superfamily is also included in Lineage I.