Genus Paraluffisphaera Esteban et al., 2005
Diagnoses: Probably free-living protists, oval in shape and with the cell surface entirely covered with two types of scales:
(1) base scales that are elliptical, flat, and with a “closed” slit in the centre, and
(2) structures resembling the base scale whose slit is open to house a tubular structure.
With the present stage of knowledge, it is not clear whether the tubular structure is attached at its proximal end to the open base scale, or if it emerges from the slit opening. No flagella or similar swimming structures were observed. This diagnosis may change if further species of the genus are found.
Type species: Paraluffisphaera tuba Esteban et al., 2005
Differential diagnosis: There is no other described eukaryote such as Paraluffisphaera – and this alone justifies its erection as a new genus. The presence of two types of scales wrapping the cell surface resembles organisms of the genus Luffisphaera – hence the generic name Paraluffisphaera. However, the organisational level of Paraluffisphaera is far simpler than that of Luffisphaera. The base and the tubular scales of Paraluffisphaera lack the lattice network configuration of Luffisphaera. In the latter, the lattice structure is present in the basal and tubular scales. The structure of this lattice network is one of the characters used for the discrimination of species. As this character does not appear in Paraluffisphaera, the segregation of species is based on the shape of the base and/or tubular scales, e.g. base scale flat and elliptical, or cup-shaped, etc. Furthermore, in Paraluffisphaera the tubular scales do not sit on prominent basal scales, as in Luffisphaera. Finally, both basal and tubular scales of Paraluffisphaera lack the conspicuous rigidness of Luffisphaera scales.