The problem is compounded by the poor preservation of organic (especially plant) materials in the recent savannah.
Some paleoindian sites, which often exhibit poor organic preservation, are a case in point.
Nevada still survives in a complete copy, but the films appearance is not the best, due probably to poor preservation.
This may be a result of poor preservation, or perhaps intraspecific variation.
The castle had been in poor preservation until 2007, when some reconstruction and renovation started.
Due to their poor preservation and geographical distance from the type species, the classification of the American forms has been contentious.
The poor preservation of the bones complicated zoological investigations.
Other features are unclear due to poor preservation.
This group is poorly known, due to poor preservation of remains despite being relatively abundant.
A new discovery, however, indicates that poor preservation is the problem.