Biggest dinosaur - the measurements

This week we looked again at that news item about the biggest dinosaur being discovered. In the news report it said that the dinoasaur weighed the same as 14 elephants.

Someone asked the question: how we could know the weight of the dinosaur from a bone measurement?

Suppose we had some weights and femur lengths from animals alive now, we could draw a line on a graph and see where the unknown ones could be. We tried it. We drew a sketch graph, added lines and some of our estimates:

But, as Rozenn pointed out, we needed a bigger graph if this new dinosaur really weighed the same as 14 elephants!

To check the measurements we looked at some data for femur length and dinosaur weight. Together we entered it into a spreadsheet and plotted a graph:

We drew a really good line right through the points:

Like this:

But, as Rozenn said, to include this new biggest dinosaur, we're going to have to make the graph bigger:

Where would the line go now?

And, given that the femur in the picture looks around 2.6 metres (or 2600 millimetres) long, using the graph, how heavy would you say the new dinosaur is?