Friday, January 27, 2012

Do giraffes have horns?


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Why: Corbett has a screensaver on her TV (wut) that is a stylized slideshow of jungle animals. One looks something like this:
What are those things?

Answer: Sorta! They used to, anyway (says Science). Giraffes are in the scientific group Pecora, which also comprises cattle, sheep, goats, antelope, and deer - all of whom have antlers.
Antlers are made of protrusions of bone which are shed and regrown each year.
The things that giraffes have, however, aren't antlers, but permanent outcroppings of cartilage called ossicones. They are in different places on the skull than antlers usually are, and they are permanently covered in both skin and fur (whereas antler velvet wears off over time). Giraffes are born with them. In evolutionary biology, this kind of thing is called a spandrel, an adaptation that once served to support some other function. In this case, the ossicones would have supported the antlers.

The way science sees it, male giraffes used to be like their antelope and deer cousins with antlers up top. They used them during mating season to fight and show dominance.
The thing is that giraffes got taller and their necks grew so long that it wouldn't have been good for them to go bashing their heads into each other anymore. (In the meantime, some extinct forms of giraffes like sivatheres had both long necks and horns:
Maybe that's why they're extinct.)
So now, since they don't have antlers up top, giraffes use these little horns at the backs of their heads to bash into each other.
They sort of wrap their necks around each other like so and go apeshit.
It's kind of embarrassing.

Source: White Souse, All Experts, Wikipedia

The More You Know: I just want to show you this awesome carousel at Jardin des Plantes in Paris, the Dodo Manège. All the animals on it are endangered or extinct! Sivathere:

Keep your eyes peeled for a dodo and a meiolaniid and an elephant bird!

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