 Though the "Beagle" departed from the Galápagos with over 30 adult tortoises on deck, these were not for scientific study, but a source of fresh meat for the Pacific crossing.Their shells and bones were thrown overboard, leaving no remains with which to test any hypotheses.It has been suggested that this oversight was made because Darwin only reported seeing tortoises on San Cristóbal ("C. chathamensis") and Santiago ("C. darwini"), both of which have an intermediate type of shell shape and are not particularly morphologically distinct from each other.