The ludicrous sizes of world-record individuals

I am no cane-toad expert, so I am only going on what this news report had to say, but apparently the average weight of a cane toad is about one pound. So this new world-record individual masses six times as much as a typical adult.

Mature male saltwater crocodiles Crocodylus porosus are typically about 4.5 m long, but the world-record verified skull length is 76 cm long indicating a total length of about 7 m. Having a length 1.56 times that of a typical individual, this beast would have massed 1.56^3 = 3.75 times as much.

There may be less variance in mammal sizes. The world-record elephant Satao massed about 11 tonnes. That’s about double the typical adult African elephant mass, which is various reported as 5 or 6 tonnes.

Now think about sauropod sizes. We have a bunch of big Diplodocus specimens all measuring on the order of 25 m in length, and massing perhaps 15 tonnes. If world-record individuals compared to these as world-record elephants do, there would have been Diplodocus individuals of twice that mass (30 tonnes); if they compared as crocs do, we should expect giant specimens massing 3.75 times as much (56 tonnes); and if they compared as cane toads do, then the factor of 6 would give us giant Diplodocus individuals massing 90 tonnes.

All of this is speculative of course — wildly so — because we have such tiny samples of Diplodocus compared with the three extant species discussed above. It’s not remotely surprising that the ten or so specimens we have don’t include a freak like this. But there’s a good chance they were out there.

Oh, and for Brachiosaurus, of which known individuals massed perhaps 30 tonnes, it’s not unreasonable to imagine giant individuals massing 60, 112 or gulp! 180 tonnes. Yes, the imagination balks at the idea of a 180-tonne land animal: but that alone is not reason enough to discount the possibility.