This work applies the X-ray MicroCT imaging technique to discuss the identification and preservation/disturbance conditions of plant remains from the Monte Castelo archaeological site, in Brazil's southwestern Amazonia. A preliminary hypothesis based on external morphological traits and the presence of typical starch grains, associates these materials to the Poaceae caryopsis. Moreover, based on their well-preserved non-charred aspect, mineralization was considered as a possible in-situ preservation process. Data from the X-ray computed microtomography (MicroCT) analysis showed that the internal anatomy of the samples corresponds to another type of fruit, described as a small drupe sharing characters with some Anacardiaceae fruits. Additionally, all studied specimens contain a number of exogenous organic and inorganic elements suggesting the action of some disturbance processes on the Monte Castelo plant material.
