Which Sauropod Is
The Largest Reptile Ever?

The largest reptile ever is a disputed title and there are several contenders for this crown. All the largest reptiles are dinosaurs, and they all belong to two families called the Diplodocids and the Titanosaurs. They are by far and away the largest land dwelling animals ever to live.

Both these groups were four footed herbivores that grew to incredible size. They are related to creatures like the very familiar Brontosaurus and Diplodocus. All these large herbivores belong to a larger group called sauropods.

Diplodocids are the kings of mega-size, but they were restricted to the late Jurassic period and by the end of the reign of the dinosaurs they were already extinct.

Titanosaurs were the last group of sauropods and lived from about 110 million years ago (the late Jurassic) to the end of the dinosaur's reign some 65 million years ago which is the end of the Cretaceous period.

They replaced all previous sauropods and by the time the dinosaurs died out they were widespread, enormous and very successful. Fossil remains of these animals have been found almost everywhere in the world with the notable exception of Antarctica.

Which Was The Biggest?

Living animals can be measured and weighed accurately. However this is not a luxury we have when looking at fossils. Scientists are pretty good at using fossil skeletons to estimate what animals looked like. Unfortunately almost all titanosaur remains found to date have been scattered and fragmented, making even length estimates approximate.

However, the amount of muscle and fat these animals would have carried around can only be estimated and this leaves us with quite a bit of overlap between the titanosaur species with regard to maximum weight. Also, a long skinny sauropod would weigh less than a shorter, stockier one. Determining the largest reptile ever is no simple task.

There is also the problem of incomplete skeletons. Some species are known from almost complete fossil remains, while at the other end of the scale some are known only from a single bone. In these cases, estimates are based on the proportions of better known and related species.

For these reasons I am presenting the three best currently known contenders for the crown of largest reptile ever.

Amphicoelias

Known from only part of one vertebra (backbone segment), this Diplodocid has been estimated at an unimaginable maximum of 60 meters in length, and tipped the scales at slightly over 122 metric tons. Its size relative to a 6 foot adult is shown below. The vertebra shown on the animal is estimated to be over 2.6 meters tall!

Sauroposeidon

Only four neck bones of this animal have been found, and these were initially mistaken for fossilized tree trunks because of their immense size. Sauroposeidon is the only mega-sauropod from the family called Brachiosaurids. It lived about 110 million years ago.

This makes it the largest reptile ever in the sense that it is the tallest land animal to have lived.

Bruhathkayosaurus

Shorter than Amphicoelias but considerably stockier, the Titanosaur Bruhathkayosaurus may well have been the heaviest land animal ever to live. It was alive in the late Cretaceous, the last part of the reign of the dinosaurs.

The fact that Bruhathkayosaurus was a land animal makes its weight even more impressive.

And The List Goes On...

As time passes more and more of these gargantuan plant eating dinosaurs are being uncovered. The sauropods are now recognized as a very diverse and successful group that was present in one form or another for virtually the entire history of the dinosaurs.

There are literally dozens of species of these giants so far discovered and more are sure to be found. It may well be the case that the largest reptile ever is still to be found.

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