''Viridiraptor'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

heterotrophic A heterotroph (; ) is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but ...

protist A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exc ...

s, containing the single species ''Viridiraptor invadens''. It belongs to the family Viridiraptoridae, in the phylum

Cercozoa Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or polyubiquitin. They were the first major eu ...

Morphology

''Viridiraptor'' are

unicellular A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Organisms fall into two general categories: prokaryotic organisms and ...

flagellate A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and their ...

d organisms that have two blunt-ended, slightly unequal

flagella A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have f ...

and a peripheral conical

nucleus Nucleus ( : nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom *Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucle ...

closer to the cell's apical end, closely surrounded by several Golgi dictyosomes in its most

anterior (anatomy) Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

half. There are cortical

extrusomes Extrusomes are membrane-bound structures in some eukaryotes which, under certain conditions, discharge their contents outside the cell. There are a variety of different types, probably not homologous, and serving various functions. Notable extru ...

distributed homogenously across the cell periphery.

Ecology and behavior

Starving ''Viridiraptor'' cells can

glide Glide may refer to: * Gliding flight, to fly without thrust Computing *Glide API, a 3D graphics interface *Glide OS, a web desktop *Glide (software), an instant video messenger *Glide, a molecular docking software by Schrödinger (company), Schr� ...

agitatedly while whipping their anterior flagellum, but they also commonly swim across the water column along a helical path. They invade dead or live cells of large-celled

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

to feed on their

protoplast Protoplast (), is a biological term coined by Hanstein in 1880 to refer to the entire cell, excluding the cell wall. Protoplasts can be generated by stripping the cell wall from plant, bacterial, or fungal cells by mechanical, chemical or enzy ...

material, and also propagate within the lumen of the devoured cell. They can also extract

plastid The plastid (Greek: πλαστός; plastós: formed, molded – plural plastids) is a membrane-bound organelle found in the Cell (biology), cells of plants, algae, and some other eukaryotic organisms. They are considered to be intracellular endosy ...

s from small-celled algae.

Etymology

The name ''Viridiraptor'' (), meaning 'robber of the green', refers to its ability to feed on the

chloroplasts A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, ...

of the green algae that it preys. The epithet ''invadens'' () is due to its ability to invade live algal cells.

References

{{Reflist, refs= {{cite journal, vauthors=Hess S, Melkonian M, title=The Mystery of Clade X: Orciraptor gen. nov. and Viridiraptor gen. nov. are Highly Specialised, Algivorous Amoeboflagellates (Glissomonadida, Cercozoa), journal=Protist, volume=164, issue=5, date=2013, pages=706–747, issn=1434-4610, doi=10.1016/j.protis.2013.07.003 {{cite journal, vauthors=Hess S, Melkonian M, title=Ultrastructure of the Algivorous Amoeboflagellate Viridiraptor invadens (Glissomonadida, Cercozoa), journal=Protist, volume=165, issue=5, date=2014, pages=605–635, issn=1434-4610, doi=10.1016/j.protis.2014.07.004 Cercozoa genera Taxa described in 2013