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Sauropod Biology

After reading everyone's thoughts on sauropods, I've decided to put all my ideas regarding them into one post. I'm not pretending to be a scientist here, I just want feedback on my ideas to see if they are plausible.

I think to get a general idea on sauropod lifestyle, we should NOT look at giraffes, or elephants or anything mammalian for that matter. The animals that should be compared with sauropods are their ancestors, the prosauropods. Consider Plateosaurus, this animal was not a high browser or a low browser, it was both. This animal was the first dinosaur to graze from *trees* high above the ground. It reared up onto its hind legs and used its large thumb claws to pull down branches, not unlike later therizinosaurs or giant ground sloths. The long neck was clearly an adaptation for high browsing from trees while in a *tripodal* position. Plateosaurus was also fully capable of low browsing. This was likely the key to sauropod success, the fact that they were able to feed from the ground equally as well as they could feed from the tree tops. Sauropods were probably generalist herbivores that could feed from any level. This may have been what allowed them to grow so large in the first place. Now, after considering the above, you will see that most sauropods retain most, if not all the same adaptations of their ancestors, only taken to the extreme. Is it really logical to think that despite having all the same adaptations of their ancestors, that their strategy for survival would have changed back into something less advantageous. With these things considered, it makes perfect sense that the neck's neutral pose would have been horizontal. If the NP was too high, then it would be a specialist high browser and would be less effective as a low browser and vice versa.

How did sauropods get blood all the way up to their tiny heads? To simply say that it was not possible for them to elevate their heads so far above their hearts, because a giraffe like system would not work, is cutting evolution a little short. Evolution has this wonderful way of coming up with many different solutions for the same problem. Look at bats, birds, pterosaurs and insects, they all fly, they all have wings, but they all have very different ways of doing it. There is no more reason to think sauropods evolved the same solution as giraffes instead of something completely different. The most likely explanation (in my opinion) is that they used peristalsis to move blood to their head. This type of system would not require extreme blood pressure. This type of pumping action is used in the digestive tract, oviducts and many other tube like organs found in animals. This system was probably the ancestor of the modern closed circulatory systems found in vertebrates. Annelids still use peristalsis to pump blood through their bodies. This system would have disadvantages though. There would be the possibility of back flow and the amount of blood that could be "carried" to the brain would probably be limited. This type of system would also require constant muscular action (like a heart) which would burn energy. This could explain why the brain is so small and why the neck's NP was horizontal. If the neck was at rest in a horizontal neutral position, the peristaltic system would not be needed until the head was raised again.

There were probably specialist sauropods such as Brachiosaurus and Dicraeosaurus. With its high shoulders, Brachiosaurus was likely a high browser like giraffes and Indricotherium, while Dicraeosaurus, with its *short* neck, was a specialist low browser. As with all specialists, these forms were prone to extinction, which is probably why the Brachiosaurs died out not long after the Jurassic.

So, in the end, what I am speculating is that Greg Paul and Kent Stevens are both right. I am suggesting that sauropods were not giant giraffes, elephants or cows, they were sauropods!

Please share your thoughts...

Sim Koning

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