world of amoeboid organisms

Menu

Pterocystidae  Cavalier-Smith and Von der Heyden, 2007

Diagnosis: Periplast ancestrally with two contrasting types of siliceous scales: tangential basal plate-scales (margin not hollow and inrolled but sometimes thickened) oval, sometimes slightly (rarely markedly) narrower at one end, sometimes slightly indented on one side (rarely slightly on both) but never distinctly bi-lobed; outer bipartite radial scales typically consisting of a leaf-like blade with an axial rib, usually extended apically as a projecting needle-like point (blunt or pointed, but not branched), and lateral wings; radial scale-base may be rounded or truncated and may be in the same plane as the blade or somewhat bent away from it (Pterocystis) or markedly extended as a distinct shelf or basal disc (sometimes called basal wing: Mikrjukov, 2002) orthogonal to the main blade (Raineriophrys); species with a pronounced basal wing may have lateral wings that are greatly reduced or absent; if silica scales are rarely secondarily missing (Chlamydaster), the cell has a distinct mucous coat; funnel-shaped scales absent.
Type genus: Pterocystis.

Included genera:

Pterocystis
Raineriophrys
Chlamydaster

The distinction between Raineriophrys and Pterocystis is not sharp; molecular and ultrastructural investigation of all other Raineriophrys species is needed to check whether Raineriophrys is monophyletic and deserves generic distinction.

Recent posts

Yogsothoth knorrus

Yogsothoth knorrus, after Shishkin and Zlatogursky, 2018 Yogsothoth knorrus Shishkin and Zlatogursky, 2018 Diagnosis: Individual cells in colony have a diameter of 5.53-13.26 µm; they

Read More »

Yogsothothidae

Yogsothoth carteri, from Shishkin and Zlatogursky, 2018 Yogsothothidae  Shishkin and Zlatogursky, 2018 Diagnosis: Centrohelids covered with two types of tangentially-oriented plate-scales, having a different morphology.

Read More »

Acanthocystis dürrschmidtidae

A. dürrschmidtidae – after Wujek, 2003 Acanthocystis dürrschmidtidae  Wujek, 2003 Diagnosis: Cells 35-40 µm (based on a whole mount). Periplast comprising scales of two types, plate

Read More »

Centroplasthelida

Centroplasthelida Febvre-Chevalier and Febvre, 1984   Diagnosis: Phagotrophic and non-photosynthetic protists with one large spherical or near spherical centrosome at the center of the cell

Read More »

Pterocystida

  Pterocystida Cavalier-Smith and Heyden, 2007 stat. n.   Phylogenetic diagnosis: The least inclusive clade, containing Pterocystis devonica, Raphidiophrys heterophryoidea and Choanocystis curvata, but not Acanthocystis

Read More »

Panacanthocystida

Panacanthocystida Shishkin et Zlatogursky, 2018   Diagnosis: Centrohelids usually covered with siliceous scales or with organic spicules: scale-bearing species with both inner plate-scales and outer

Read More »