tertiarii

Tertiary is a term used in several different contexts, primarily in the fields of education, geology, and biology. In education, it refers to the third stage of learning, typically higher education such as universities and colleges, following primary and secondary education. This stage focuses on specialized academic study and research.

In geology, the Tertiary period is an older classification of geological time, now largely superseded by the Paleogene and Neogene periods. It historically encompassed the era from the extinction of the dinosaurs (about 66 million years ago) to the start of the Quaternary period (about 2.6 million years ago). This era saw the diversification and dominance of mammals and the formation of many major mountain ranges.

In biology, "tertiary" can refer to an organism's trophic level. A tertiary consumer is an animal that eats secondary consumers. These are typically apex predators at the top of the food chain, such as lions or eagles, which are not typically preyed upon by other animals. The term can also be applied to tertiary structures in proteins, describing the overall three-dimensional shape of a single polypeptide chain, including interactions between side chains.