The stegosaurus in "The Land Before Time" may have been portrayed as a harmless sweetheart, but new research suggests this type of dinosaur was a ferocious fighter when it needed to be.

Researchers found a stab wound in the pubis bone of a predatory allosaur, the injury was in the conical shape of a stegosaur tail spike, the Geological Society of America reported. Inflicting that type of wound on an attacker would have involved impressive dexterity on the Stegosaurus' part, and the unfortunate allosaur is believed to have died from the wound.

"A massive infection ate away a baseball-sized sector of the bone," said Houston Museum of Natural Science paleontologist Robert Bakker and his colleagues, who present a poster on the discovery on Tuesday at the meeting of the Geological Society of America in Vancouver, B.C. "Probably this infection spread upwards into the soft tissue attached here, the thigh muscles and adjacent intestines and reproductive organs."

The severity of the wound can be compared to those seen in rodeo cowboys who are gored by longhorn bulls. Many modern species, such as buffalo, defend themselves with their horns; these ancient beasts are now believed to have done something similar, except with their tails. Past research suggest stegosaur's tails had more dexterity than what was seen in most dinosaurs.

"They have no locking joints, even in the tail," Bakker said. "Most dinosaur tails get stiffer towards the end."

In order to inflict the fatal wound the stegosaur would have had to move its tail underneath its opponent and twist the tail upwards, which is believed to have been possible judging by the flexible dinosaur's anatomy.Despite their impressive fighting ability the author's noted the stegosaur had one of the smallest brains for its body of any larger animal in history.