The ancient bones of a distant ancestor of the modern giraffe they are offering scientists evidence as to why the animal’s long neck developed.
Scientists say these fossils, which were discovered in China, suggest a long neck was useful for male competitions.
Researchers recently described the fossils including a thick skull, or strong head bones and neck bones. They belonged to one of the earliest members of the giraffe family called Discokeryx xiezhi. The creature lived about 17 million years ago in the Xinjiang area of northwest China.
Discokeryx’s solid skull and sturdy neck bones were fine adapted to high-speed direct confrontations. They were like the competitions seen between males of some mammal species for females, the researchers said.
They explained that Discokeryx had the most complex neck bones of any mammal. This was the case with the joints between the head and neck, as well as between the individual bones of the neck.
Discokeryx means “disc horn”, while xiezhi is a one-horned creature in traditional Chinese stories. Discokeryx’s skull had a large, round, thick bone structure known as the ossicone. This is the name of the horn-shaped objects on the tops of giraffes’ heads.
Shi-Qi Wang Wang, lead author of the study published in Science, said: “Ossicones, like horns and horns, usually serve as weapons for males to fight for mates.”
Study co-author Jin Meng said the traditional idea as to why modern giraffes have such long necks is that long necks are useful for eating tree leaves. “Discokeryx most likely ate herbs,” Meng explained.
Meng added: “This new discovery shows that, in the giraffe family, members do different things in the beginning Evolution. The new species represents an extreme example where the neck … gets very thick to absorb the power and impact from a powerful header. “
Another idea about the evolution of the giraffe’s neck – supported by Discokeryx’s bone structure – is that the neck elongation was driven by the behavior shown in competition for mates such as the “neck” seen in giraffes today. In such competitions, males hit themselves violently with the neck. Longer necked males often win these fights.
“If a male giraffe has a shorter neck, the female can refuse the male’s mating request,” Wang said.
Neck elongation or elongation evolved independently between different groups of animals hundreds of millions of years ago.
Discokeryx, the researchers said, could offer insight into early developments in giraffe neck elongation over millions of years.
Discokeryx, however, has embarked on a different specialized evolutionary path for warheads. It is not considered a direct ancestor of today’s giraffe, but rather a secondary development of the giraffe family.
The modern giraffe, found in Africa south of the Sahara Desert, is the tallest living land animal in the world. Males can grow up to 5.5 meters in height and females up to 4.3 meters in height. A giraffe’s neck, which spans about 1.8 meters, has only seven neck bones like other mammals.
Discokeryx lived in open grasslands with small clusters of trees during a period known as the Miocene period. He lived alongside ancient elephants, rhinos, pigs, deer and horses. predators at the time it included saber-toothed cats, hyenas and a member of a group of mammals called the “dog bear” – a creature the size of a modern polar bear.
I’m John Russell.
Will Dunham reported this story for Reuters. John Russell adapted it for VOA Learning English.
Words in this story
giraffe – n. a very tall African animal that has extremely long neck and legs
fossil – n. something (such as a leaf, a skeleton or a footprint) that comes from a plant or animal that lived in ancient times and that you can see in some rocks
Evolution – n. the process by which changes in plants and animals occur over time
to adapt—V. change (something) so that it works better or is more suitable for a purpose
impact – n. the act or force of one thing affecting another
predator – n. an animal that lives by killing and eating other animals: an animal that preys on other animals