Alveolate

The alveolates are a group of protists, considered a major clade or superphylum within Eukaryota. They are currently grouped with the Stramenopiles and Rhizaria among the protists with tubulocristate mitochondria into the SAR supergroup.

==Characteristics== The most notable shared characteristic is the presence of cortical (near the surface) alveoli (sacs). These are flattened vesicles (sacs) arranged as a layer just under the membrane and supporting it, typically contributing to a flexible pellicle (thin skin). In armored dinoflagellates they may contain stiff plates. Alveolates have mitochondria with tubular cristae (invaginations), and cells often have pore-like intrusions through the cell surface. The group contains free-living and parasitic organisms, predatory flagellates, and photosynthetic organisms.