Large flying fox fox was one of the many mammal species originally described by Linnaeus in the landmark 1758 10th edition of his "Systema Naturae", receiving the name "Vespertilio vampyrus". The large flying fox is among the largest species of bat. It weighs and has a wingspan of up to . Its head-body length is . As with all megabats, it has a fox-like face, hence its name. It lacks a tail and has pointed ears. The hairs on much of its body are long and woolly, but are shorter and more erect on the upper back. The mantle hairs tend to be
Guam flying fox a length of about , a wingspan of about , and a body weight of . It is very similar in appearance to the Chuuk flying fox ("Pteropus insularis"). The top of the head is greyish, the back, throat and underparts brown or dark brown and the side of the neck golden-brown. Little is known of the behaviour of this flying fox but it is likely to have fed on the fruits, flowers and foliage of evergreen shrubs and trees typical of the limestone forests that occur in the northern part of Guam. Nor is much known of its reproductive