Stegosaur's tail packed a lethal punch

by Mary Caperton Morton
Monday, January 5, 2015

The stegosaur tail spike entered the allosaur's pubis and passed all the way through the bone. The wound then led to an abscess and infection that eventually spread and killed the allosaur. Credit: Robert Bakker.

With their big lumbering bodies and plates of armor, stegosaurs can be likened to the modern-day rhinoceros. Both are primarily peaceful plant eaters, but you wouldn’t want to make either of them mad. Now, paleontologists have uncovered evidence of a casualty of stegosaurian combat: a predatory allosaur with a lethal conical wound the size and shape of a stegosaur tail spike.

The stab wound was found in the pubis bone of the allosaur, a place that would have taken great dexterity on the part of the stegosaurus to reach. “A massive infection ate away a baseball-sized sector of the bone,” said Houston Museum of Natural Science paleontologist Robert Bakker, who presented a poster on the discovery at the annual Geological Society of America meeting in Vancouver, B.C. “Probably this infection spread upwards into the soft tissue attached here, the thigh muscles and adjacent intestines and reproductive organs,” he said in a statement. The lack of any signs of healing strongly suggests the allosaur died from the infection, he said.

Previous discoveries have hinted that stegosaurs' tails were more flexible than other dinosaur tails of similar size, with no locking joints and massive muscles at the base of the appendage. “The joints of a stegosaur tail look like a monkey’s [flexible] tail,” Bakker said. Stegosaur tails “were built for 3-D combat.”

© 2008-2021. All rights reserved. Any copying, redistribution or retransmission of any of the contents of this service without the expressed written permission of the American Geosciences Institute is expressly prohibited. Click here for all copyright requests.