Amargasaurus Cazaui

KA-ZOW-EE!! Man, I love saying that out loud. It surely has to be one of the most satisfying names in the fossil record!

But the beautiful name is only the start of Amargasaurus' charms, as this little study will hopefully show:

Restoring this chap presented a lot of problems, not least the fact that, as shown in the vector diagram, the only remains we have to go on come from just three known specimens, all incomplete. These have provided a complete picture of the main body of the skeleton, but the head and feet are still missing. Hence, in restoring this species, I have supplanted the skull and foot bones of a close relative: Dicraeosaurus Hansemanni. 

Copyright A V S Turner

But the shapes of the missing parts aren't nearly so troublesome as the bits that are present. The extraordinary elongated prongs on the cervical vertebrae pose a baffling problem. Traditionally, these have been supposed to act as supports for sail-fins, which presumably would have acted much like the dorsal plates of a Stegosaurus - acting both as an elaborate display to attract mates/deter predators and as a 'central-heating' system; radiating heat away from the body in extreme temperatures.

However, more recent theories propose that Amargasaurus' lengthy spines were more likely to have stood proud of the main trunk of the neck and would have been sheathed in horny tissue'. Hence, I have opted to style this species with bare horns. I have assumed (again, because I have been unable as yet to find any explanation) that the reason for abandoning the sail-fin theory is because such a set-up would have limited the range of motion in the animal's neck, making it a poor and unlikely adaptation (I will post any further information as I find it).

Also, it occurs to me that if you observe large predators (Lions, crocodiles, wolves etc), bringing down large prey, the killing blow is generally struck on the neck. This is because eviscerating an animal until it bleeds to death is a messy, time-consuming and exhausting affair. Crushing the windpipe or suffocating the victim (as lionesses do, by taking the snout of a wildebeest in their own mouth to cut off the air supply) is far more effective.
And when one considers that the neck on most Diplodocids is the most exposed part of the animal, it is tantalyzing to me to think how many diplodocids might have met their ends having their slender necks crushed in the jaws of moderate-to-large sized predators.
Amargasaurus' exposed spines would have acted as an effective deterrent against such attacks.

However, I must admit, I do not wholly agree with the bare-horns restoration either, if only because it also looks so impractical (I know, it's not a very scientific argument, plus there's nothing particularly 'practical' about Amargasaurus in any case!).
Plus, as a student of animal behaviour and evolution, I'm afraid  I just can't resist using the vertebral spines of Amargasaurus to suspend a moderate pair of sail-fins. These would not be so cumbersome as to restrain the movement in the animal's neck and would act as a canvas for elaborate patterns. Such an adaptation would:

a) Allow animals within a group to identify one another by the patterns on the sail (the specimen shown here is male; I have given him a bright blue tinge to his mini-sail so he can really show off to the lay-dees...)
b) Enlarge the animal's silhouette, making it appear larger and more threatening to predators (crowned with bare horns, Amargasaurus would appear even more so)
c) Radiate heat away from the head and neck in extreme weather


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