Penard Labs

Penard Labs
Heliozoa Haeckel 1866, stat. n. Margulis 1974, emend. Cavalier-Smith 2012
Phagotrophic and non-photosynthetic protists with one large spherical or near spherical centrosome at the centre of the cell and numerous radiating axopodia. Axopodia always with extrusomes that are either kinetocysts or tiny dense ellipsoids.

1. Centrohelea Kühn 1926, stat. n. Cavalier-Smith 1993
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.

1.1. Pterocystida Cavalier-Smith 2012
Silicified species always with both plate and spine scales; plate scales oval without an inrolled margin; spine scales (spicules) radially asymmetric, ranging from a shape like a pointed moss leaf with axial rib, through reduced forms with the blade restricted to the base, to a vertical stalk emanating from a notched asymmetric basal disc.

1.1.1. Pterocystidae Cavalier-Smith and von der Heyden 2007
Periplast ancestrally with two contrasting types of siliceous scales: tangential basal plate scales; outer bipartite radial spine scales, usually extended apically as a projecting needle-like point.

Including: Pterocystis, Raineriophrys, Chlamydaster, Echinocystis.

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Stacks Image 8387

1.1.2. Choanocystidae Cavalier-Smith and von der Heyden 2007
Periplast with two contrasting types of siliceous scales, oval or bilobed tangential basal plate scales; outer bipartite radial spine scales consisting of a vertical stalk, sometimes curved or branched but lacking lateral wings. Funnel-shaped scales absent.

Including: Choanocystis.

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Stacks Image 4642

1.1.3. Heterophryidae Poche 1913
Centrohelids lacking silica scales but with numerous thin pointed organic scales tapering towards acute apices.

Including: Heterophrys, Sphaerastrum, Parasphaerastrum.

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Stacks Image 4790

1.2. Acanthocystida Cavalier-Smith 2012
Silicified species with both plate and spine scales or only plate scales lacking a hollow inrolled margin; outer radial spine scales radially symmetric, present in one or both of two forms: funnel-shaped with apical flared and toothed funnel on a stalk and a discoid base, or needle-like with a radially symmetric peltate base and/or apical branches.

1.2.1. Chalarothoracina Hertwig and Lesser 1874, emend. Cavalier-Smith 2012
Always with silica scales.

1.2.1.1. Acanthocystidae Claus 1874, emend. Cavalier-Smith and von der Heyden 2007
Periplast with two or three types of siliceous scales, a basal layer of typically oval plate scales and an outer layer of radial funnel-shaped siliceous spine scales and/or radial needle-like spine scales sometimes apically branched and/or with a peltate radially symmetrical basal disc lacking a lateral indentation.

Including: Acanthocystis, Raphidocystis, Pseudoraphidocystis.

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Stacks Image 4882

1.2.1.2. Raphidiophryidae Mikrjukov 1996, emend. Cavalier-Smith and von der Heyden 2007
Periplast typically containing tangential siliceous plates surrounded by a hollow marginal rim but never goblet-shaped or other radial spine scales.

Including: Raphidiophrys, Pseudoraphidiophrys, Polyplacocystis, Heteroraphidiophrys.

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Stacks Image 4956

1.2.2. Marophryina Cavalier-Smith 2012
Periplast lacking silica scales but with numerous thin, pointed organic spicules tapering towards acute apices.

1.2.2.1. Marophryidae Cavalier-Smith and von der Heyden 2007
Spicules radially oriented, numerous, length approximately half the cell diameter, tapering abruptly from base to acute tips.

Including: Marophrys.
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Stacks Image 11535