Saturday, August 23, 2014

Spinosaurus Is Weird

This tiny picture is all that we have for the new Spinosaurus. This dinosaur never ceases to amaze me. It is most well known in that is beat up Tyrannosaurus in Jurassic Park 3, and of course, that fight could not have happened like that for multiple reasons, and these new discoveries seem to make it even more implausible. It turns out, Spinosaurus had a dip in the sail, sort of like Ichthyovenator. What is also shows is the arms are small, but the legs are tiny, yet probably robust. It would seem implausible that such a huge animal was supported by tiny legs like those. It would make it do a face plant on land, but in water it seems like the best way to get around. The feet appear to be small, so maybe not swimming, but possibly walking on the river bed. This shows that Spinosaurus really is more aquatic than we ever assumed.

To counterbalance the heavy front end, it would need a massively long tail. So, it seems like it was more than just semi-aquatic. However, that leaves a burning question: how could it have walked? If its feet were tiny, how? was reading a discussion on the Dinosaur Toy Forum about this, and some people gave some suggestions of how. As said above, it could have had a long tail to counterbalance it. Another person gave the suggestion of maybe it splayed its legs slightly to spread its weight. I find the former more plausible, but the feet are small. However it did walk, it would look awkward, and otherworldly.

But, this is not really news. It has been online for about a year now, but for some reason finally became big this year. A few interesting things as well. Paul Sereno, who discovered the new remains, said that the above picture is inaccurate. So, that begs the question, what is inaccurate about it? Did its sail not have an impression? Were its feet actually normal sized? That we won't know, until the paper can be published. Until then, we will continue to speculate the habits of this remarkable creature.

Friday, August 15, 2014

The Leaellynasaura Theory

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.

Monday, August 4, 2014

Kulindadromeus Changes the World

First off, I know I am late to this. Now, since last year, there was rumour of an ornithischian from Siberia with feathers. It was called "Kulindodromeus". Well, it is finally described, but is called "Kulindadromeus". This has got to be the coolest thing going on here. As an ornithschian with feathers, this little herbivore has provided the best evidence that all dinosaurs had some sort of feathering. What is more, is that the earliest dinosaurs had feathers. Ornithischians and saurischians evolved not long after the first dinosaurs appeared. So feathers probably evolved before that split occured.

You also have pycnofibers on pterosaurs, and the ancestors pterosaurs split off before the first ancestors of dinosaurs appeared. Feather like filaments probably evolved in the early Triassic, before that pterosaur/dinosaur split occured. However, before we say that this is absolutely true, we have to do some sort of skeptical work. Some people have suggested that feather like structures evolved several times in the dinosaur line. However, I don't think so. I think that these feather-like filaments on Kulindadromeus are homologous with those on theropod dinosaurs. While we have the best evidence of an entire line of feathered animals to date, the final proof would probably be a very early dinosaur with feathers.

This also had me think about feathered sauropods. Before this, I never really thought sauropods were feathered. But, it had me thinking. Sauropods are saurischians, and the majority of feathered dinosaurs are saurischians. My very speculative theory, is that when born, young sauropodlets possessed  downy feathers, like those of a newborn chick. However, overtime, I think that the young gradually lost the majority of feathers, with only their feet having feathers when fully grown. I have no proof of this, but it is entirely possible. Also, this is further proof of endothermy in dinosaurs (not that it needed much more proof), and that endothermy goes even further back on the archosaur line than thought. Also, crocodiles have dormant feather producing genes, and this seems to support that too.