proto-

Original or first; primitive or ancestral.

Greek prōtos, first.

Examples include prototype, a first or preliminary model of something; protohuman, a hypothetical prehistoric primate, resembling humans and thought to be their ancestor; protomartyr, the first martyr for a cause, especially the first Christian martyr, St Stephen; protostar, a contracting mass of gas which represents an early stage in the formation of a star; protoplast (Greek plassein, to mould), the protoplasm of a living plant or bacterial cell whose cell wall has been removed; Protozoa (Latin plural of Greek zōion, animal), a phylum or grouping of phyla which comprises the single-celled microscopic animals.