Introduction:
Amargasaurus is one of the weird and fascinating forms of a classic dinosaur body plan. We all know that Sauropods or Long-necked herbivorous dinosaur body plan with a long-neck, long tails, massive bodies, 4 tall legs and a small head on top but Amargasaurus is built a bit different because not only is it a little smaller, still big enough to squash any small dinosaur, but 2 rows of tall neural spines growing out of the neck. This is one of the most weirdest adaptation for any dinosaur to have, and for a Sauropod no less. Any dinosaur or prehistoric creature usually have 1 row of tall neural spine but Amargasaurus has 2 which makes it so strange for such an adaptation to evolve. Well let’s go into more detail about this unique genus of a Sauropod.
Discovery:
Amargasaurus was discovered back in 1984, in the La Amarga Formation which is one part of the three formations in Argentina where it was discovered. Unfortunately, there has been no new finds of this dinosaur however, the fossils found was a virtually complete skeleton. Super lucky to find a skeleton even with fragmentary skull. That makes Amargasaurus one of the best-known sauropods. Sauropod skulls are hard to come by because of their small size and fragile nature. Many Sauropod that we have found, a lot of them are skull-less and so paleontologists have to compare and contrast to find out in which family they belong and that makes it easier to think what kind of skull it might have. For Amargasaurus, they were lucky!
The name Amargasaurus cazaui, comes from the Spanish word for ‘bitter‘ and Greek word for ‘lizard‘ making it ‘amarga sauros‘ and the species name ‘cazaui‘ is in honor of a Geologist with the YPF oil company, Luis Cazau, who controlled this part of the formation. Luis Cazau told the paleontologists, Jose Bonaparte and Guillermo Rougier, the potential of this formation having dinosaur fossils which led to the discovery of Amargasaurus and some other dinosaurs as well. It is because of him, the paleontologists were able to discover the Amargasaurus and thus added his last name with an ‘i’ to honor him. This is how most of the time species naming works, especially for paleontology.
You might be thinking if you have heard the name ‘Jose Bonaparte‘ and you would be right because he is also the paleontologist who discovered Carnotaurus sastrei. Don’t forget to check out that post either and do let me know if I should do more species profile discovered by Jose Bonaparte!
Biology:
Now, you might have heard that people say Amargasaurus is a pretty small sauropod for a being a sauropod but I mean, look at the size comparison with a human. A herd or well-aimed stomp would instantly flatline you, no question. Amargasaurus grew up to be 3 m (10 ft) tall and estimated to be around 9 to 13 m (30 – 40 ft) long with weight being around 2.6 – 4 tons. And the spines would be at least the size of a small dog, coming around 24 inches (2 ft). The neck, while being shorter than most other sauropods, was around 2.4 m (7.9 ft). But the astonishing feature of this dinosaur would be the tall neural spines which starts from the neck and head connection running down to, at the very least, to the tail.
Amargasaurus was a member of the strangest sauropod group, Dicraeosauridae. A group that consists of relatively short-necked sauropods which came from the superfamily of Diplodocoidea. Diplodocoidea had a lot more subfamilies which includes Rebbachisauridae, Diplodocidae and yours truly, Dicraeosauridae. It is quite astonishing turn of evolution as Diplodocus being one of the largest sauropods to come in Jurassic Period and then the later group becoming one of the smallest sauropods. The paleontologists have found that the earliest divide happened in the Middle Jurassic Period because both Dicraeosauridae and Diplodocidae were sisters from the common ancestors.
You might not know but Dicraeosauridae has a lot of other genera of dinosaurs like the Suuwassea, Lingwulong, Dicraeosaurus, Brachytrachelopan, Amargasaurus, Amargatitanis, Pilmatueia, Tharosaurus, and newest genus discovered, Bajadasaurus. I am planning to make more post about other Dicraeosauridaes in the future and so, do let me know down in the comments which one you want to see first!
Let’s get into the meat of this dinosaur’s feature which are the tall neural spines. You might think it just sticks out from the back of the neck like the spiked tail of Stegosaurus but it was not like that. Rather, it was more like a sail like that of Spinosaurus and Ouranosaurus and many more sailed animals. And to make it cooler, it had two sails or a pair of sails. For a long time, paleontologists thought that Amargasaurus spines were protected by keratin like our nails and used as defense against carnivorous dinosaurs, intimidation amongst themselves and as well as a display feature for attracting mates. While it does sound plausible but further research showed that Amargasaurus spines actually had a layer of skin over it and also had blood vessel marks over the bones. If the spines were protected by a keratinous sheath, then their could not have been any sort of blood vessel marks or the bones or the chemical function of the bone would not show that it supported a layer of skin and that is how we can say that the spines of Amargasaurus is truly covered by skin or had a pair of sails.
Amargasaurus lived around Early Cretaceous when dinosaurs started to become even more diversified and many lineages came from. The Argentina at that time was quite varied with many odd kinds of sauropods like the Zapalasaurus, Amargatitanis, as well as yet to be named basal titanosauriforms. With many different kinds of sauropods in one ecosystem, paleontologists surmised that different sauropods occupied different niches of the ecosystem with Titanosaurs occupying the tall trees while the shorter and smaller sauropods feeding on ground-level and low-level vegetation. Other genera of this ecosystem include a yet to be named stegosauridae, a small ceratosaur Ligabueino, as well as another large Allosaurus-type carnivore evidenced by the teeth fossils, along with an extinct form of crocodilian which is part of an extinct family, trematochampsid, Amargasuchus and this was found alongside Amargasaurus.
Media:
With Amargasaurus’ uniqueness, it was sure to become popular among the Entertainment Media. So popular in fact that 2 Pokemon are based off Amargasaurus, Amura and Aurorus. It is very rare to see Pokemon being based off actual dinosaurs are always fun especially to see how some inspiration did come from dinosaurs but not told outright.
But Amargasaurus not only made an appearance in Pokemon but a whole host of other media as well like how Disney’s CG-animated film, Dinosaur, was supposed to have an Amargasaurus with a clubbed-tail but was cut from the film. I don’t know where they got the idea for a clubbed-tail and I am probably guessing they mixed it with Shunosaurus when researching for sauropods. Thankfully they did not add that dinosaur because the film already has some major inaccuracies.
It also made an appearance in ‘The Land Before Time X: The Great Longneck Migration‘ but the screentime was fairly little and the design is not that great. It also showed up in a National Geographic documentary, Bizarre Dinosaurs, for a brief moment where the paleontologists talked about the spines and sails of Amargasaurus. The design is okay for the documentary but could be better.
On the Japan side of things, Amargasaurus was in the Fossil Fighters Frontiers game as well as Dinosaur King where as for the game, it did look a bit weird but for the Anime, it did look really good and accurate for the time.
I am not quite well-versed with Dino Dan & Dinosaur Train but Amargasaurus did make an appearance and it is pretty accurate with the sail part of the neck but they kind of overdid it by making it all the way to the back which Amargasaurus did not have in real life.
And finally in the Jurassic franchise, Amargasaurus did make appearance through the smartphone games, Jurassic Park: Builder, Jurassic World The Game, Jurassic World: Alive and not only that but it made it’s latest appearance in Jurassic World Evolution 2. For Jurassic Park: Builder it only has 1 sail which does continue through the back which is inaccurate and for the World apps, the Amargasaurus does have 2 rows of spines but also no sail on the back of the neck but on the actual back which makes it a very odd decision. The Amargasaurus in Jurassic World Evolution 2 is an improvement in all of those mentioned design, it does with a little inaccuracy where the neck spines are not covered with a sail but the sail research did come out in 2022 while the game came out in 2021 which makes it unfortunate but I feel this is the best from all the designs. Surprisingly, one more design in the Jurassic brand is accurate and it came out a lot earlier, Jurassic World Dino Rivals toyline brought an Amargasaurus with 2 rows of sails and a little smaller sail on the back which may be a creative liberty but accidentally accurate on the neck spines.
Q&A:
What dinosaur is similar to Bajadasaurus?
This is an excellent and for a long time, paleontologists thought Amargasaurus was probably one of a kind dinosaur but recently, in the year of 2019, Bajadasaurus pronuspinax, was revealed to the public after a long 9-years of research. Yes, sometimes researching, discovering and all that stuff take a long time. Bajadasaurus also had similarly spiked neck like Amargasaurus but in place of curving backwards, they curved forward which was rather odd. Later on, it is now thought to be a relative of Amargasaurus and put in the same family, Dicraeosauridae. Let me know if you want to know more about Bajadasaurus in a separate post and I will gladly make a post about it.
What is special about Amargasaurus?
I mean, if you just take a little peek, you can see why. There has been no sauropods with such a spined-neck like Amargasaurus and not only that, but the fossils found for this dinosaur is of a fairly complete skeleton. You do not usually find such a dinosaur and not only that but as strange and different as an Amargasaurus is even more unlikely. The neck spines are so tall and now we know that it was more like a sail makes it so much more different and special than many other dinosaurs.
Are Amargasaurus aggressive?
Well, no. Not exactly because even though it looks intimidating with the spined sails, it was probably not aggressive. What you have to understand that all animals can be aggressive but it depends on how you act in front of the animal. Herbivores, especially, will usually be more calm and not aggressive but if you provoke them or hurt them or make them feel that they are in danger, well of course they are going to be aggressive. Any provoked animal will be aggressive and dangerous and so it is best not to provoke the herbivores for your own safety.
Did Amargasaurus have any predators?
Amargasaurus definitely had predators and all ecosystems of any age will have a predator, that is how an ecosystem works. The spined sail probably acted as a defense against smaller predators but larger predators probably had less of a problem but the thing is that the fossil formation Amargasaurus was found in, yielded nothing much about theropod dinosaurs as I have stated earlier in this post. So, I guess in this Amargasaurus did not have any predators, for now until more fossils are discovered.
Was Amargasaurus fast?
For a sauropod with a smaller size and lower weight, there is a chance it could have run fast but it is only just a hypothesis because sauropods are not built for running and sure there could have been some light sprinting and running from predators but that is where the spined sails come in handy and it could deterred the predators as they would not be able to bite the vital parts. So probably with some fast running due to a smaller build and defensive sails helped Amargasaurus surviving in the Early Cretaceous South America.
Merchandise:
Well, here we are at the end of this post about Amargasaurus and with the popularity it has gained from the unique spines on a sauropod comes with varieties of merchandise and here are some that I have found. While unfortunately I was not able to find the Jurassic World Dino Rivals Amargasaurus because of it’s poor distribution and limited release that it is only in eBay and I do not want my readers to pay scalping prices for an action figure that should be enjoyed by many but have a look at all the other alternative action figures which are super interesting as well.
And thus you have reached the end of the post about Amargasaurus. I hope you have learned something new today and I hope to see you again in more of other posts. If you have any suggestions about what I should cover next, let me know down in the comments and see you again next time in another of my posts.