The giraffe’s distinctive long neck may have evolved* from males bashing heads while battling it out for a female mate.
Fossilised* remains of Discokeryx, an early member of the giraffe family that lived about 17 million years ago, revealed a solid skull, thick neck and strong cervical vertebrae* perfect for high-speed, head-to-head combat, according to the researchers.
Over the course of millions of years, the animal’s head and neck “adapted for headbutting behaviour,” said American Museum of Natural History palaeontologist* and study co-author Dr Jin Meng.
“The traditional hypothesis* for … elongation* of the giraffe neck is eating – reaching up to get tree leaves,” Dr Meng said. “This new finding shows that, in the giraffe family, members do different things in their early evolution.
“The new species represents an extreme example in which the neck … becomes very thick to absorb the power and impact from powerful headbutting.”
The Discokeryx was named “disc horn” for its helmet-like skull with horn-like knobs known as ossicones, which are still present in modern giraffes.
“Ossicones, like horns and antlers, usually serve as weapons for males fighting for mates,” said Chinese Academy of Sciences palaeontologist Dr Shi-Qi Wang, lead author of the study published in the journal Science.
Discovered in the Xinjiang region in northwestern China, researchers said the skeleton had the most complex head and neck bones of any mammal and was roughly the size of a large bighorn sheep.
Discokeryx lived in open grassland with patches of trees and shrubs during the Miocene era. It lived alongside shovel-tusked elephants, hornless rhinos, horned pigs, deer with crown-like antlers, three-toed horses and various antelopes.
“Discokeryx most likely ate grasses,” Dr Meng said.
Predators* included sabre-toothed cats, hyenas and a mammal called “dog bears”, which were as big as a polar bear.
Giraffes today still strike each other in a move known as “necking”. Longer-necked males often win these duels – and they may also get the girl.
“If a male giraffe has a shorter neck, then the female may refuse the mating request of the male,” Dr Wang said.
Discokeryx is not a direct ancestor but a side branch of the giraffe family. The modern giraffe, hailing from sub-Saharan Africa, is the world’s tallest living land animal. Males measure up to 5.5m and females are up to 4.3m tall, with the neck stretching up to 1.8m, the longest of any animal on Earth.
- evolved: developed, changed or adapted slowly over time
- fossilised: remains preserved as a fossil, in this case the remains of a skeleton
- cervical vertebrae: series of neck bones directly below the skull
- palaeontologist: scientist who studies fossils to determine the history of life on Earth
- hypothesis: theory, idea, proposition
- elongation: process of becoming or making something longer
- predators: animal that naturally preys on other animals for food
- How long ago did this new species live and in what era?
- What is the traditional theory or hypothesis for the length of a giraffe’s neck?
- What are ossicones?
- Is Discokeryx a direct ancestor of the giraffe family?
- Why are the animals thought to have been fighting?
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1. Evolution of the giraffe
Draw a sketch of the Discokeryx giraffe and modern giraffes that live today.
Label the similarities and differences of your two sketches to compare the changes in the giraffe over time.
Time: allow 25 minutes to complete this activity
Curriculum Links: English; Visual Arts
Write an acrostic poem on a “giraffe” and facts you know about them.
Time: allow 20 minutes to complete this activity
Curriculum Links: English; Critical and Creative Thinking
Wow word recycle
There are plenty of wow words (ambitious pieces of vocabulary) being used in the article. Some are in the glossary, but there might be extra ones from the article that you think are exceptional as well.
Identify all the words in the article that you think are not common words, and particularly good choices for the writer to have chosen.
Select three words you have highlighted to recycle into your own sentences.
If any of the words you identified are not in the glossary, write up your own glossary for them.