This is strange. From the comments here I can only conclude the WTS has changed its ideas about creation. Been a long time 'out' but certainly back in the 70s the official view that there was no 'time of creation' for the universe or the Earth. In fact I remember a line from one of the publications actually saying that any suggestion that the Earth was just 6000 years old was 'absurd'.
The seven 'days' of creation were of indeterminate length. There was some oblique comment in the Greek Scriptures that suggested 6 or 7 thousand years but I always felt the JW chronology was about looking at things that weren't actually there.
At the time of my zombie-like faith-adhering ways I'd assumed the dinosaurs were the 'monsters' referred to in the early part of Genesis. Only tells you what you need to know...right? Turned out to be what they thought the knew but that's a another story.
Dinosaurs wiped out in the flood? I suspect mankind would have spent more time building better walls than sinning if those things were wandering around looking for lunch. No one has ever seen a living T-Rex. Even the fossil record shows this.
The early dinosaur reconstructions were more about getting the punters in than scientific accuracy, even allowing for the lack of knowledge at the time. Early palaeontologists were not exactly low on ambition. Check out Sir Richard Owen and be grateful you never worked for him.