February 19, 2008

Giant ‘Frog From Hell’ Fossil Found

Paleontologists from University College London (UCL) and Stony Brook University in New York have identified a giant frog fossil from Madagascar, given the name Beelzebufo (pronounced bee-el-zeh-BOOF-oh), which means "Ëœthe frog from Hell'.

The fossil is 70 million years old, and of a type once thought unique to South America, providing evidence for a new theory that Madagascar, India and South America were linked until late in the age of dinosaurs.

The frog resembles today's living Horned toads in having a squat body, huge head and wide mouth. However with a body length of up to 16 inches and a weight of around 10 pounds, the bowling-ball sized frog is more than twice the size of its largest living relatives.

The scientists said Beelzebufo did not live an aquatic lifestyle, but instead, lived in a dry environment and may have hunted like its modern-day relatives, which camouflage themselves and spring out at their prey.

"This frog, a relative of today's Horned toads, would have been the size of a slightly squashed beach-ball, with short legs and a big mouth. If it shared the aggressive temperament and "Ëœsit-and-wait' ambush tactics of living Horned toads, it would have been a formidable predator on small animals. Its diet would most likely have consisted of insects and small vertebrates like lizards, but it's not impossible that Beelzebufo might even have munched on hatchling or juvenile dinosaurs," said Susan Evans of UCL's Department of Cell & Developmental Biology, in a UCL press release about the discovery.

The fossil challenges assumptions about ancient geography, and calls into question the commonly accepted timeline of when the Southern continents of India and South America drifted apart. It's commonly believed that during Beelzebufo's time what is now Madagascar would have long been separated by ocean from South America.

However, frogs can't survive long in salt water, said lead paleontologist David Krause at New York's Stony Brook University. Krause believes the giant frog provides evidence for competing theories that a land bridge connected the continents much later than previously believed, perhaps via Antarctica before it became the frozen land mass it is today.

The land bridge would have let animals move overland among those continents. Indeed, fossils have been found of other animals in Madagascar from Beelzebufo's time similar to South American ones.

"Madagascar has a mainly endemic frog fauna whose history has generated intense debate, fuelled by recent phylogenetic studies and the near absence of a fossil record. Our discovery of a frog strikingly different from today's Madagascan frogs, and akin to the Horned toads previously considered endemic to South America, lends weight to the controversial paleobiogeographical model suggesting that Madagascar, the Indian subcontinent and South America were linked well into the Late Cretaceous period. It also suggests that the initial spread of such beasts began earlier than that proposed by recent estimates," the scientists said in the press release.

The first frogs appeared approximately 180 million years ago, and their basic body plan has remained unchanged. Beelzebufo lived during the Cretaceous Period at the end of the age of dinosaurs, which along with many other animals became extinct 65 million years ago after giant space rocks hit the Earth.

Scientists found Beelzebufo's first fragmentary fossils in1993, and have only recently assembled enough fragments to piece its remains together like a jigsaw puzzle, Krause told Reuters.


On the Net:

Proceedings of the National Academy of Sciences (PNAS)

University College London

Stony Brook University