Does No Skull Mean Fake?

[Macrophyseter]

Ive made a topic about the largest animal on earth on a different forum, saying, it's the 200 foot long amphicoelias fragillimus. But someone replied that a skull of it has not been discovered, and if no skull has been discovered, the creature is not real. Now, there is a debate on that on my post, but I quit that forum. But is it really true? That no skull = not real???

[connorp]

Definitely not true. While obviously helpful in identification, a skull is not needed. Many extinct species have been described only from a few isolated bone fragments, often vertebra or leg bones.

The problem with A. fragillimus is that the only info concerning it is field notes and sketches. Only a few bone fragments were ever found and all have disappeared, which has lead some to call into question the extremely large size measurements of the bones. But until more fossils are found, there will never be any real consensus on the size of this sauropod.

[izak_]

Well, I am kinda with you and kinda not :/ Just because no skull was found, doesn't mean it doesn't exist. It may have been disarticulated or something.

OR, they may have stuffed up the identification

Not saying those scenarios are correct, but, you know, just what I think

Oh, this could be late but, Welcome To TFF!

[painshill]

Surely it’s not the absence of the skull per se that creates the controversy here, but the general lack of physical evidence and the assumptions Cope and others have made about scaling by comparison to related genera where we have more complete skeletons? In the specific case of Amphicoelias fragillimus, all we had was a partial dorsal vertebra consisting of the neural arch and spine in rather poor condition and believed to be D9 or D10. Cope also mentions an otherwise undescribed “immense distal end of femur” in his field notes not too far from where the vertebra was found, that likely belonged to the same individual.

Neither of those bones still exists in any collection that we know of and it’s generally believed that the partial vertebra may have disintegrated shortly after collection. So all we have are Cope’s measurements of the partial vertebra, which some have disputed as “exaggerated” (given that the find was made in the “bone wars” era when palaeontologists were seeking to trump one another with ever more impressive finds). That’s probably rather unfair on Copes, but he left us only a single drawing of the vertebra, viewed from the posterior end only and – as far as I know – no drawings at all of the broken femur, nor any measurements.

Cope’s original assumptions estimated the size of a complete femur based on the premise that it would have been twice as long as the tallest dorsal vertebra and extrapolated to the size of the complete animal by comparison to other sauropods. In fairness to Cope, more modern estimates using Diplodocus as the reference point don’t contradict his estimates and even the conservative ends of the spectrum put A. fragillimus at a size beyond anything else we know of.

I would also just point out that “size” here, means “length”, not body mass. Given that the animal certainly must have had a very long and progressively tapering tail, any speculation about snout-to-tail dimensions of the animal itself could be distorted by false assumptions about exactly how long that tail might have been. If we take body mass as a measure of size, then extant blue whales are certainly “bigger” than any known dinosaur, although not “longer”.

[amour 25]

Is this that Large one they found what 10 years back in SA.

Super something or other?

Just a leg bone?

[painshill]

Is this that Large one they found what 10 years back in SA.

Super something or other?

Just a leg bone?

No, this was Edward Cope's find of 1877 in Colorado (or rather, a find by one of his team of collectors).

[jpc]

Well, darn... I guess our T rex does not exist. What should I say to my volunteers who have been working on it for three or four years?