Out of all the times in Earth's history, the most interesting was the Cretaceous, second was the Permian. Out of all the countries in the Cretaceous, Australia was the most interesting. It is full of surprises, and animals that live nowhere else on Earth. And out of all those animals in Australia, one was adapted to the polar conditions, better than any in my opinion. My all time favourite dinosaurs; Leaellynasaura amcigraphica. This post is dedicated to my most interesting of ornithopods.
Leaellynasaura is known from little material, a skull and some tail vertebra. But we know a few interesting things from those isolated fossils. The skull housed a huge eye, and it was very useful for seeing in the dark, which would last up to five months, since Australia was connected to Antarctica. The tail is the defining feature of Leaellynasaura. It is three times longer than the head neck and body combined. So, what could it have been used for? Well, we need to look at the environment at the time. There were no polar ice caps in the Cretaceous, but the early Cretaceous did experience some cold temperatures, especially compared to the late Cretaceous, which was incredibly warm. Because of the presence of trees, that the climate was warmer than Antarctica today, but it wasn't implausible that it didn't snow of get below freezing. With this, we can speculate what the tail is used for. Because it's very long, we can imagine it being bushy, and so Leaellynasaura likely had feathers (Kulindadromeus). If the feathers didn't protect it from the cold, they could use their bushy tail to wrap around the body, and keep it warm. This is further supported by the fact that the tail was very, very flexible, and not stiff, easily capable of wrapping around its body. The tail may also have been used as a decoy. If a predator were to attack, they could make themselves bigger than they are by puffing up their tails. They could also use it in sacrifice to save its body. Confuse the predator to go for the tail, and not the body.
But the rest of the post is going to be my speculation on the rest of Leaellynasaura. We don't have a rest of the body, especially the arms and feet, so I am going to use wild speculation. I don't think it's implausible that little Leaellyn had wide feet to navigate through the snow. The feet wouldbe fully feathered of course, and be used like snowshoes. And it's legs would be the most powerful part of little Leaellyn's body. The arms may have been tiny, almost vestigial, with little use. Of course, we have no evidence for the second part, but sometimes Polar Animals evolve bizarre features for apparently no reason.
In the end, we may never know about little Leaellynasaura, but in the end, it really is the most interesting dinosaur of all. With the longest tail length in comparison of it's body of all dinosaurs, it surely will not be mistaken by the generic ornithopods.