In ecology, paleoecology uses the data of fossils or subfossils to reconstruct the ecosystems of the past.

The study of fossil organisms in terms of their life cycle, their interactions, their natural environment, their manner of death and burial.
Paleoecology's aim is therefore to build the most detailed model possible of the life environment of those organisms we find today as fossils; such reconstruction work means facing complex data pools, themselves expression of complex interactions between environmental factors (temperature, food supplies, degree of solar illumination etc.) On the other hand the opposite is also true, and the lack of data caused by the post-mortem fossilization processes is a problem to be taken into account.
The environmental complexity factor is normally tackled through statistical analysis of the available numerical data (quantitative paleontology or paleostatistics), while post-mortem processes as a source of information are the field of application of taphonomy.