They can serve as direct evidence that a specific plant or animal existed in a certain place at a certain time.At Charleston Quarry in eastern Illinois, for example, a glacier overrode a spruce forest.In addition to the many plant and animal fossils in the paleontological collections, the Illinois State Museum is home to the North American Fossil Pollen Database.Scientists contribute pollen data from study sites throughout North America to add to this body of information.They often refer to the Cretaceous as a time of transition.Charles Darwin referenced the sudden appearance of fully-formed flowering plant parts in the fossil record as an “abominable mystery” in a letter to Joseph Hooker in 1879, and these new blooming fossils only intensify the puzzle.Our understanding of the shape and pattern of the history of life depends on the accuracy of fossils and dating methods.

Each kind of flowering plant produces pollen that is unique and pollen grains have tough coverings that can last a long time.Pollen analysis is then calibrated with SYNONYMS OR RELATED TERMS: APFCATEGORY: measure DEFINITION: A pollen density measure in which pollen counts per unit volume of sediment are corrected by estimated deposition rate (depth per year) to estimated influx (counts per cm per year), the same unit used for pollen rain" in modern samples.Each taxon varies independently of the others making interpretation much easier than with percentages."SYNONYMS OR RELATED TERMS: pollen analysis CATEGORY: related field; technique DEFINITION: The study of fossil and living spores (of lichens and mosses) and pollen (of flowering plants); the technique through which the fossil pollen grains and spores from archaeological sites are studied.Preserved evidence of plants and animals (footprints left in wet clay, preserved wastes, stains left in sediments) are also considered fossils.Fossils occur at natural sites (in caves, in lake sediments, etc), as well as at archaeological sites (places where human activity occurred).