Fossils unearthed in China of the ancestors of giraffes today have provided insight into the evolution of The long neck characteristic of mammals, which is useful not only for reaching tall foliage but also for head-butting competition among males for a mate. The ancestor of the giraffe evolved a long neck that relied on the butt of the head, to defend its position and dominance over females, according to a new study published this week in the journal. Sciences.
Since Darwin’s time, the giraffe, the tallest mammal in the animal kingdom, has been a classic example of adaptive evolution.. And thehe is Discokeryx xiezhi It is the name of a newly discovered species of the giraffe family. He lived 17 million years ago, and was not much taller than the current large deer. The fossil of this new species was discovered in northern China.
Fossilized bones were discovered in northern China more than 20 years ago by Paleontologist Jin Meng, who is currently responsible for fossil mammals in American Museum of Natural History in New York City. A new analysis of the discovery by Meng and colleagues has revealed characteristics of mammals that could help us better understand the forces involved in developing the giraffe’s unique anatomy.
named after The mythical unicorn goat In Chinese lore, the newly described Discokeryx xiezhi was designed to be an ancient member of the super family Giraffoidea. Who roamed the Miocene savannah About 17 million years ago.
What stands out most about D. xiezhi is not its graceful proportions, but its stocky, skull-clad physique reminiscent of a medieval infantry helmet. Flat, wide and with a small brim, it’s the perfect type of helmet to withstand a confrontation or two with a competitor.
This conformation, the researchers said, “may have been adapted to combative behaviors, through head-banging among the males”.. This behavior can be compared to the current fights of “male giraffes on their necks”. Present-day male giraffes by throwing their heads, equipped with small horns, fight against the opponent with all their might.
Male giraffes use their necks to fight, not their heads. In the article the authors stated that the evolution of these elongated petioles could have been for fighting rather than just reaching for the foliage. “Here, as in classic case studies, behavior may have strongly influenced morphological evolution, with extreme behavior leading to severe morphological evolution in graphoids,” they note in their paper.
“The bottom line is that the head and neck structure in giraffe families is very diverse, as revealed by the new fossils. These specialized shapes reflect the diverse lifestyles of these animals,” Meng said.
For a long time, paleontologists defended the idea that the long neck was a necessary evolution to reach the leaves of trees. The theory of origin regarding the need to establish her sexual dominance is more recent and controversial.
The new study by Shi-Qi Wang and colleagues adds another piece to this theory: At first it was the fights that caused the neck to grow, then it ended up benefiting his way of eating.
“It is an excellent example of ‘acquiescence’, that is, an organ that bestows an advantage and then becomes useful for another purpose,” explained Grégoire Metis, a paleontologist at the Museum of Natural History in Paris. The ancestors of today’s giraffes embarked on an evolutionary “race” to achieve a long, well-bolstered neck, this expert explains.
This once again shows that sexual competition is one of the drivers of evolutionwhich leads to morphological innovations that can be used for other purposes,” said the French paleontologist.