Hungarian Natural History Museum, Giants of Patagonia - Dinosaurs of Argentina - ブダペスト, ハンガリー

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GPS座標： の緯度 47°28'56"、の経度 19°5'8" (N47 28.93 - E19 5.13) マップ

The Carnotaurus sastrei, a great carnivorous dinosaur

The bipedal (walking on the two rear legs) theropod Carnotaurus is special but not only because of its appearance. This was a large carnivorous dinosaur with extremely small forelimbs, as well as unique horn-like structures over its eyes. Interestingly almost a complete skeleton was excavated, and to top it all in a natural position (it was laid in a so-called hematite mineral inclusion). The most unique discovery was that beside the bones also skin imprints were remained from this 8-meter-long animal that was weighing 1200 kilograms and lived about 80 million years ago! This kind of paleontological find is very-very rare, this valuable fossil type can answer a lot of things, that the bones alone cannot. For example it can be recognized that the skin of the Carnotaurus was covered by evenly spaced bumps and it looked similar to the skin of the present pachyderms (thick-skinned mammals).

Amargasaurus cazaui, a member of the sauropod dinosaurs, although it is smaller than its relatives, it is even more interesting

The herbivorous (plant eating) Amargasaurus dinosaur was explored in Argentina, it was named after the Amarga Stream ("Arroyo La Amarga") which is close to the exploration site. All of our knowledge is coming from this as of today only one explored fossil of this species, however this is in quite good conditions. The exhibited skeleton in the temporary exhibition of the Hungarian Natural History Museum ("Magyar Természettudományi Múzeum") is of course just a replica.

The front leg of the Megaraptor namunhuaiquit with giant claws

The science is not set in stone, even it sounds stange when talking about prehistoric fossils. Here is a great example for this case. The paleontologists could be very surprised when not so long ago it was revealed that the hind leg of a big bipedal predatory dinosaur called Megaraptor namunhuaiquit is actually its foreleg. This dinosaur was known based on only a single fossil for long time, which was a giant, at least 30-centimeter-long razor-sharp sickle-shaped claw. As its scientific name shows this animal was first classified as a member of the raptor family, which are usually small or medium sized fast theropoda dinosaurs, walking on two legs, and each hindfoot has a big sickle-shaped claw.

However, the tables were turned when a complete forelimb of a Megaraptor was found, with the already known giant claw on its first finger. This has made it clear that it couldn't be a raptor but something else. Based on further new discoveries the relationship of the Megaraptor is slowly taking shape, for example the allosauroid Australovenator from the Cretaceous Period could be probably one of its relative.

It is sure that it was big, but the exact appearance can be only assumed and still questionable. After 2007 the "Giants of Patagonia - Dinosaurs of Argentina" exhibition came back to the Hungarian Natural History Museum ("Magyar Természettudományi Múzeum") in 2013 again, and then the whole imaginary complete skeleton of the Megaraptor already could be seen. It was created based on the explored foreleg and the anatomy of the animal's relatives.

So what's the lesson? The science is flexible, newer knowledges, proven findings or rational arguments can even completely upset the previous theories. Among other things this enlightened approach distinguishes it from for example the religions and other dogmas, where the smallest spark of the divergent thinking could lead event to a war. Most of the times the religions say they know the truth, but the science modestly satisfied the fact that it just tries to find it.

In this certain case in the scientific knowledge the hind leg of an animal "became" foreleg in few years, but of course this change took place in a peaceful way even in the scientific community, because why wouldn't they believe their own eyes.

Skull of the Amargasaurus cazaui plant-eating (herbivorous) sauropod dinosaur

The plant eating sauropod dinosaur group (Sauropoda) was consisted of mostly giant animals, the Amargasaurus which was lived about 130 million years ago was relatively small compared to them. Its strange teeth could be even frightful, but these are just very practical: these were evolved to collect the plant food. The sauropods used their teeth like a comb, they "ripped off" all the leaves from a branch with one movement then swallowed them without chewing. The food procession exclusively depended on their very long and special digestive tract.

A larger animal has longer digestive system, so the body can process the food for longer time, and due to the same reason a large animal can eat even lower quality food. The primary target was the fast eating, therefore the more rapid growth. It is no wonder, because the big size was the major weapon of this prehistoric reptile group agains the predators. Probably that's why the bone spikes on the neck of the Amargasaurus were evolved, to somewhat compensate the relatively smaller size of this sauropod dinosaur.