Two giraffe, Giraffa camelopardalis giraffa, stand together silhouetted by a sunset, necks crossing


Two giraffe, Giraffa camelopardalis giraffa, stand together silhouetted by a sunset, necks crossing

Photo by: Mint Images

Mint Images

Why the Long Face? Extinct Headbutting Relatives Reveal Giraffes' Neck Evolution

Pioneered by Darwin, giraffes have been used as a classic example of how animals adapt and evolve. Giraffe’s long-neck evolution has long been attributed to foraging for sustenance in the high canopy, now researchers argue that selection for head-butting combat played a role in the long length of giraffe necks.

June 28, 2022

Researchers at the Chinese Academy of Sciences’ Institute of Vertebrate Paleontology and Paleoanthropology have been studying the Discokeryx xiezhi, a fossil relative of the Giraffe. In 1996, the fossil was found in China’s northwestern Junggar Basin and since then more fossils of the same species have been discovered. During its initial discovery, researchers were confounded by the unusual skull and vertebrae. Within the Discokeryx xiezhi, scientists found thick craniums with disklike headgear, thickened cervical vertebrae, and complex head and neck joints unlike any ever seen.



In recent years, the Chinese research team found that the unusual fossil belongs to a giraffoid, helping them use the past to understand the present evolutionary trait. While many believed the giraffes' long necks evolved to allow them to reach their tall foliage meals, giraffe behavior showed another essential purpose. Giraffe’s long necks are also used to compete for female attention during courtship and mating rituals. When comparing the structure of their horns with cattle, sheep, and deer, the research team found that giraffes have larger variations in horn formation. Their analysis suggests that giraffe mating competition is more intense than their horned mammal adjacent.

Within the giraffe social hierarchy, males with the longest neck are at the top and this trait becomes a force of why giraffe necks evolved to be so long. Shiqi Wang, study author and associate professor at the Chinese Academy of Sciences’ Institute of Vertebrate Paleontology and Paleoanthropology, explains the evolution patterns of the giraffe and their relatives stating, “Both living giraffes and Discokeryx xiezhi belong to the Girraffoidea, a superfamily. Although their skull and neck morphologies differ greatly, both are associated with male courtship struggles and both have evolved in an extreme direction.”

By studying Discokeryx xiezhi’s tooth enamel, scientists have determined their living environment, in open grasslands with patchy bushes and trees. During the Miocene period (17 million years ago), Earth was covered in lush vegetation and warmth. Within the giraffoid’s home, the Xinjiang region had a more arid climate with a more barren habitat that caused the species to have more environmental pressure to survive. This climate caused more intense fights for female giraffoids. These giraffe relatives were forced to evolve and develop “necking”, the neck-fighting style to succeed in mating rituals. This adaptation caused the modern giraffe’s neck to grow and evolve over the years.

This team hopes to discover more fossils so that the information can be used as a comparison with other mammals and dinosaurs.

Next Up

The Oldest Complete Fish Fossil was Discovered Thanks to Kung Fu

Back in 2019, three Chinese paleontologists were playfighting during a break from working in the Chongqing Province, China. One was kung-fu kicked into a rocky outcrop, causing rubble to tumble down and exposing an opening in the rock face. Inside, a spectacular fossil lay undisturbed, preserved for millions of years.

Are Whale Sharks Now the World’s Largest Omnivore?

A new study finds that whale sharks are the biggest omnivore, disproving previous research on whale sharks’ diets. Researchers were stunned when analyzing whale shark biopsy samples that contained lots of plant material as well as krill material.

Two Orcas Are Hunting Great White Sharks in South Africa

A killer whale duo has been killing great white sharks off the Gansbaai coast, causing them to flee the area. These orcas have developed a taste for shark livers, transforming the local marine ecosystem.

Is Climate Change Killing More Elephants than Poachers?

Kenya’s Wildlife and Tourism Board has announced that climate change is now a bigger threat to elephant populations than poaching. Kenya is currently facing an extreme drought that is threatening the livelihoods of people and wildlife within the area.

99% of Sea Turtles are Now Born Female. Here's Why.

Global warming is creating a crisis in sea turtles' gender ratios, where 99% of them are being born female. Sea turtle populations have been facing a significant population decline further exasperated by climate change.

The Ancient Monkey Puzzle Tree Outlasted Dinosaurs. Now It's Facing Extinction.

The monkey puzzle tree is a remnant of the Jurassic era, more than 145 million years ago, surviving way past its ancient dinosaur counterparts. Reaching heights of about 160 feet, the evergreen tree has a lifespan of up to 700 years and stiff scaly branches with rigid spiral leaves. Monkey puzzle trees’ presence in the wild is shrinking and after million years, their very existence is now endangered.

Are Sharks Coming Closer to Our Shores?

Scientists at the University of Miami Rosenstiel School of Marine and Atmospheric Science have speculated that variables related to high urbanization may be driving higher occurrences of sharks within coastal waters. With high increased levels of urbanization in coastal cities, it’s important for our world to understand how ocean life adapts to the changes in their habitats.

There is Hope for the Future of Polar Bears Threatened by Climate Change

Scientific researchers have recently identified a sub-population of polar bears in southeastern Greenland that survive by hunting on glacial slush. The discovery of their unique behaviors is helping scientists understand the future of this species whose habitats are threatened by climate change.

One Who Causes Fear: Dinosaur Species Discovered in Patagonia

Paleontologists and researchers discovered a meat-eating species of dinosaur identified as “one who causes fear” in Patagonia.

The World’s Deadliest Bird Used to be a Pet

Scientists found cassowary eggshells in New Guinea showing the lethal bird was being domesticated 18,000 years ago.

Related To: