What is the term for the remains or an impression of a plant or animal?

The term that describes the remains or an impression of a plant or animal is "fossil." Fossils typically form when organisms are buried under sediment, which over time can lead to the preservation of their structure through processes like mineralization. This means that the original material of the organism is gradually replaced by minerals, or the organism leaves an impression in sediment that hardens into rock. Fossils provide significant insight into the history of life on Earth, as they offer clues about the physical characteristics of ancient organisms, their habitats, and the environment in which they lived.

Other terms such as "specimen," "artifact," and "remnant" do not specifically refer to the remains or impressions of biological organisms. A specimen often refers to a sample taken for scientific study, typically of a living organism or a part thereof. An artifact pertains to objects created or used by human beings, particularly those of historical or archaeological interest. A remnant could refer to any small remaining quantity of something, but does not specifically imply the preservation of biological material in the way that fossils do.