A quick Google turns up this page:
http://www.strangeark.com/strange/mammals.html
Quote:
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The Giant Fossil Vampire Bat
A giant vampire bat, Desmodus draculae, was found fossilized in a cave in the State of Monagas, Venezuela. The total humerus length of this fossil was 51 mm, compared to an average of 37 mm for Desmodus rotundus, an extant species of vampire bat. The skull length for D. draculae was 31.2 mm. D. r. rotundus has an average skull length of 24.8 mm. The author suggested a late Pleistocene age for this species, but could not rule out a Recent age, so it's possible that this species still survives. Actually, vampire bats aren't that big anyway, so this giant species isn't monster-sized, but it would still be interesting to see.
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Now, the remaining question is where does the connection to 'ancient man' come in? What evidence is there that these existed in the same place with humans and that humans killed them off? That I found no sign of. So if you want to know you'll have to contact the author of that article and ask about the 'giant vampire bats' and any evidence that they interacted with humans.
[ May 27, 2003, 23:18: Message edited by: Baron Munchausen ]