[BroJoeK]

The Cajun: "A walking whale. It had to be pushing the size limit of what's possible on land from the anatomical physics alone."

Windflier: "Per simple logic, gravity had to have been weaker in those times, or the planet itself was smaller."

Windflier: "Those are heretical thoughts, I know, but nothing else makes sense to me."

Here we go again...

Whole books have been written pro & con such lunatic ideas.
The "con" arguments take considerably more effort to understand, but I recommend it.

Here's the pro from 2010:

The Paradox of Large Dinosaurs (The New Science Book 2) [Kindle Edition]

And here is the con, from 2011:
Biology of the Sauropod Dinosaurs: Understanding the Life of Giants (Life of the Past) [Kindle Edition]

[SunkenCiv]

Hey, bees can’t fly. :’)

[Windflier]

Wassamatta - you don’t like science heretics?

[The Cajun]

I remember, way back when in school, where we were taught dinosaurs like the Brachiosaurus were the biggest land dinosaurs that could exist and they also had to live in swampy areas where water would help support their tremendous weight.
Well lookie here what we got, one nearly twice the weight of a Brachiosaurus that wasn't fully grown.
Have read articles about the atmospheric influence, gravitational influence, etc, etc.
I just find the arguments one way or the other interesting, but come right down to it, it's all just theorizing and fun to theorize to boot.