This week's post is partly inspired by Sir David Attenborough and Ben Garrod's one-off TV special, Attenborough and the Giant Dinosaur, which is on BBC1 at 6.30pm tonight - don't miss it ! Read about it here.
I spent Christmas and New Year in Northern Ireland. Belfast is home to one of my favourite museums - the Ulster Museum - which has a particularly cool skeleton of a Triceratops horridus. Triceratops are one of the best known dinosaurs, along with the T-rex, which I wrote about here.
There are two types of Triceratops - T. horridus and T. prorsus. They are very, very similar, with the only differences being in the skull shape. They were both found in North America and Canada, but they were alive at different times. I first saw a Triceratops skull for real at the Galerie de paléontologie et d'anatomie comparée in Paris in 2011:
The skull
The first fossil was a partial skull and horns that was found in Denver in 1887. The word Triceratops is Greek for three horned face, and it's pretty obvious why this name was chosen from looking at the skull. The three horns on the skull were used to fight and protect itself from predators such as the T-rex, which was also alive around the same time as the Triceratops. They were both around in the late Cretaceous Period (around 65 million years ago)
Triceratops were gigantic animals, which could grow up to eight metres long ( not including the tail ), and stand three metres tall. One cool fact about them is that their skull are the biggest skulls in the world - the longest found so far being 2.5m long - and the top two horns can be over a metre long.
It's not sure what the spikes were used for - Triceratops was a herbivore, so it's not to attack prey. It's now thought they could have been for the males to fight each other over females, and also to show from the size which ones were "dominant" - as well as defending from attackers That's pretty much the same function as antlers have in some deer (such as red deer), although these spikes were permanent (like sheep horns) and antlers are shed each year.
The beak is unusual - and the mouth is tiny compared to the size of the animal. It must have spent its whole day grazing to eat enough for its massive body.
Teeth
Triceratops's teeth were unusual. Over the course of their life, their teeth are constantly replaced, just like sharks, and there were up to 800 teeth in the mouth at one time - although only a small number would be grinding food at any one time, with the others stacked underneath, waiting to emerge. There would be up to five teeth in each stack, and up to 40 stacks in each of the four sides of the mouth (top-left, top-right, bottom-left, bottom-right).
Scapula and spine
The scapula is very weirdly shaped. It is very flat and long and most similar to birds. It's hard to understand how such a small scapula can have all the muscle attachments needed for such a strong animal, especially as the ridge down the middle (confusingly also called a spine) isn't very tall.
The shape is unlike many modern day mammals - here's some I compared a few years ago.
Tail
Their tail helped balance the weight of the head, and, like the Stegosaurus, it could have used it for defence - although unlike Stegosaurus, it doesn't have spikes on the end to use as a weapon.
Pelvis
The pelvis of the Triceratops is very unusual, unlike any other land animal I can think of. The closest animals that I've seen with a pelvis like this are birds. The pelvis is very flat and the lowest vertebrae are attached to the pelvis.
In birds, this kind of pelvis allows strength and lessens weight for flight. It reduces flexibility on the lower spine, but Triceratops was such a heavy animal - up to eight tons - that it probably didn't need flexibility which is usually needed for jumping or running.
Toes
They had three hooves at the front, and four at the back. The extra toe on the front on this skeleton appears to be vestigal - as in, left over from evolution but not used any more. Unlike the T-rex, Triceratops walked on four legs and walked flat footed.
Legs
The leg bones and short and thick, showing they have evolved to support a massive weight, and quite different from animals evolved for speed. Here you can see how robust and thick the humerus is here., with lots of areas for muscle attachment.
The back leg bones - the humeri - look very thin and flimsy from the side angle, but are much thicker from the front.
Make sure you watch Attenborough And The Giant Dinosaur today on BBC one at 6:30pm !
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