A fossil found 50 years ago on the Philippine island of Cebu has been identified as the bones of an extinct dwarf species of buffalo.
The finding, detailed in the October issue of the Journal of Mammalogy, is the first well-supported example of "island dwarfing" among cattle or their relatives and could have implications for the current debate about Homo floresiensis, a hominid discovered three years ago on the Indonesian island of Flores that some scientists say is a new dwarf species, not a new human species.
"Natural selection can produce dramatic body-size changes. On islands where there is limited food and a small population, large mammals often evolve to much smaller size," said lead researcher Darin Croft of Case Western Reserve University in Ohio.
Named Bubalus cebuensis (BOO-buh-luhs seh-boo-EN-sis), the miniature buffalo was just two feet tall, three times smaller than today's domestic buffalo, and weighed only 350 pounds. It probably lived during the Pleistocene (Ice Age) or Holocene Epochs, between 10,000 and 100,000 years ago.
Paleontologist John Flynn of the American Museum of Natural History in New York, and other scientists examined the partial skeleton, which included two teeth, two vertebrae, two upper arm bones, a foot bone and two hoof bones. The species had relatively large teeth, which is typical of island dwarfs, but also relatively big feet, which are generally reduced along with other body features in dwarfing.
The reason that might be is because evolution actually works in different ways -- we call it mosaic evolution -- that not all features change in exactly the same way all the time," said Flynn. "For whatever reason, this particular species didn't reduce the foot proportions the same way that dwarfs of other species on other islands might have."
Fossils finds are rare in the tropical environment of the Philippines, a region with scarce open rocky areas where fossils are often buried and preserved. This is the first fossil mammal of any age reported from Cebu Island.
The fossil remains were found 50 years ago in a phosphate mine by engineer Michael Armas. Nearly 40 years later, he showed them to physician Hamilcar Intengan. Intengan took them to The Field Museum for study in 1995.
The finding supports the idea that the earliest water buffalo were large and first evolved in Southeast Asia. The animals probably traveled from the mainland to the Philippine islands when sea levels dropped roughly 400 feet(130 meters) during the peak of the ��Ice Age�� about 20,000 years ago. Enditem