An illustration of Gobisaurus, an ankylosaur with a stiff tail but no knob of bone at the end. Sydney Mohr Arbour was interested in examining what part of this weapon evolved first.

An illustration of Gobisaurus, an ankylosaur with a stiff tail but no knob of bone at the end. (Image credit: Sydney Mohr) The knob, or the large ball-type object at the end of the tail, was made ...

The key differences between the sexes lie in bones near the base of the tail. For the study, the team examined a pair of fossils unearthed in Mongolia in the mid-1990s and first described in 2012.

But if the tail-bone measuring technique does work, being able to determine dinosaur sex just by measuring a few bones offers tantalizing possibilities, potentially revealing previously unknowable ...

Wolf packs typically include a male-female breeding pair that leads its offspring and nonbreeding adults, according to the U.S. National Park Service. Tail wagging during greetings is one of many ...

The bones were unearthed by Simon Ferguson and his sons as they dug a hole for a pond in Thornton-Cleveleys. "The skull was like the wolf was jumping out of the ground," said his 12-year-old son ...