Prodromus

A prodromus ('forerunner' or 'precursor') aka prodrome is a term used in the natural sciences to describe a preliminary publication intended as the basis for a later, more comprehensive work. It is also a medical term used for a premonitory symptom, that is, a symptom indicating the onset of a disease.

Notable prodromi were Prodromus Entomology, Prodromus Florae Novae Hollandiae et Insulae Van Diemen, Prodromus Systematis Naturalis Regni Vegetabilis and Nicolas Steno's De solido intra solidum naturaliter contento dissertationis prodromus, one of the early treatises attempting to explain the occurrence of fossils in solid rock.