Since the Jurassic Park movies came out pushing Velociraptors as large carnivores. The Paleo-Scientific evidence has always ridiculed it's 'inaccurate' portrayal of their sizes (and of Mosasaurs, etc) as typical Hollywood rubbish (understandably going by track record of most Hollywood stuff).

But this time, Hollywood got it right!
Just recently, fossil tracks of Raptors have been discovered in CCP land proving they were much larger than Humans after all.
https://www.msn.com/en-au/news/australia/raptor-dinosaurs-much-bigger-than-previously-thought/ar-AA1nFnWP?ocid=msedgntp&pc=ACTS&cvid=e53fb899508c456df909ad011a46cef7&ei=13

'The atmosphere of the Earth 80 million years ago was discovered to have 50% more oxygen than modern air. Brenner and Landis found that for all gas samples taken from amber 80 million years old the oxygen content ranged between 25% to 35% and averaged about 30% oxygen. Cretaceous air was supercharged with oxygen.'
This implies vigorous plant growth to feed the beasts and hyper-active feeding and body-building. The smart money was on speed to out-run the explosive bush-fires.

Wait for the series :-   Aborassic Park ....... Gone To Gondwanamo Bay .......... The Boys of Abo's Graves ...

The Chinese raptors has prompted a discovery of maga-raptors in Montana US. Rex 'Dino' Clawman, a twinkly eyed, chuckling lizard-scientist has turned up the great American raptor. At 39m. height with 3.6m. long slashers, it ripped any Chinese chook into shredded feathers and land fill. 'These guys stood tall for all Americans and the flag in which we sail. Bless them' he sang with tears.

True. The atmosphere was thicker with oxygen and denser.
Thus such 'huge' sizes of Dinosaurs were more 'buoyant' so to speak and why such huge Pterosaurs could fly around in a more supportive atmosphere against gravity.
You could say they were almost like 'swimming' through the air - it was that rich on oxygen.

Anyone who dives with Nitrox 32% or 36% like I do, know the benefits (but depth restrictions) over just plain 'air'.

All the decaying organisms in oil were bubbling up with methane, producing a rich high-octane fuel ratio for turbo charged pterodactyls (Mk I- III, patented). The raptors had rooster fights where they accelerated to 180kmh on the runway and collided. This was banned due to concussion injuries.

;D