However, recent work has suggested that the pollen was perhaps introduced to the burial by animal action, as several burrows of a gerbil-like rodent known as the Persian jird were found nearby. The jird is known to store large numbers of seeds and flowers at certain points in their burrows and this argument was used in conjunction with the lack of ritual treatment of the rest of the skeletons in the cave to suggest that the Shanidar 4 burial had natural, not cultural, origins. Paul B. Pettitt has stated that the "deliberate placement of flowers has now been convincingly eliminated", noting that "A recent examination of the microfauna from the strata into which the grave was cut suggests that the pollen was deposited by the burrowing rodent "Meriones persicus", which is common in the Shanidar microfauna and whose burrowing activity can be observed today". Despite his conclusions that flowers were unlikely to have been deliberately placed, Petitt nevertheless concludes that the Shanidar burials, because they happened over so many years, represent a deliberate mortuary practice by Neanderthals.