Vegetated deposits termed as middens are present in many caves and rock shelters of the arid southwestern United States. Middens are basically a blend of plant and animal fossils sheathed in crystallized packrat urine. If explained in archeological terms, midden or mound is more or less a pile of garbage. These are used to recreate past vegetation and climate in the abrupt area of the midden deposit. Till the time, the midden is prevented from water, such as under a rock ledge, it will remain as it is. Packrat middens are matured using radiocarbon dating. Moreover, fossil middens have been found that were older than 50,000 years which is the realistic limit of aging them using radiocarbon dating. From time to time, scientists have been conducting studies on such middens to understand past climate variability. The studies have also helped them in analyzing the course of future transforms in the earth’s climate system. Also, the research enables them to explore and learn ancient time’s climate changeability by reconstructing vegetation change as preserved in Packrat Middens.

The enormous importance of Packrat middens or mounds in paleoecological research remains unquestionable. They totally serve the requirement of the preserved plant and animal material, which is eagerly identifiable and idyllic for macrofossil examination. Along with plant and animal microfossils, packrat middens also may enclose pollen, epidermal fragments, and microfossils. Initially, these deposits were discovered in 1960 at Indian Springs Ranch, around 65 kilometers northwest of Las Vegas, Nevada. Throughout the caves and rock crevices of the arid west, the packrat middens are omnipresent. Here, they can rest preserved for millions and millions of years. Over a thousand of such deposits have been dated and analyzed. Moreover, middens have succeeded pollen records as a standard for learning vegetation dynamics and climatic change in radiocarbon time. In fact, now, similar deposits prepared by other mammals like hyraxes in the other parts of the world are also being studied.

Many researchers have introduced interesting speculations and investigations of fossil middens in the United States, Mexico, Africa, the Middle East, and Australia. The contributions have largely laid the platform for methodological concerns, revising the fossil record of various geographic regions, introducing fresh applications, and showing the huge latent for fossil midden analysis in arid regions worldwide. Each discovery of packrat midden promotes regional research and encourages general studies dedicated to global climate change. So far the studies have suggested that in the coming future, plant communities will transform both position and character because of growing global warming. Instead of normal movement of plant communities, climatic change is also going to change according to different plant species.

Summary: Fossilized packrat middens are imperative in paleoecological rebuilding of precedent climate because of the plant and animal matter they hold. This material is accumulated by the packrat within a radius up to 100 meters from their dens, and mainly, constitutes of sticks, twigs, and other plant material.