Centripetal acceleration at the equator is R ω^2 = (radius of the earth) * (2 * pi / 24 hours)^2 = 0.0337 m/s^2 .

Acceleration due to gravity is 9.8 m/s^2, so you weigh 0.3% less in Singapore than at the North Pole. (There are other factors, like the Earth's bulge, which I won't consider.)

This small enough that people don't notice it. (Presumably dinosaurs wouldn't either.) Plus, most people don't live on the equator, and there's a cos(latitude)^2 factor which reduces the centripetal acceleration. At 45 degree latitude the acceleration is 1/2 that of the equator.

Speed up the Earth's rotation to 23.5 hours and it's 0.0352 m/s^2.

The difference is 0.0015 m/s^2 , which is quite small compared to the normal force of gravity.

Thus, it isn't really important for most things.

Thanks for the response, and for doing the math. After reading your response it I agree that it wouldn't have much more effect than an increase in elevation. I thought it might explain how the dinosaurs were able to grow so big without collapsing under their own weight(which probably can be explained too)

https://www.thoughtco.com/why-were-dinosaurs-so-big-1092128 suggests the reasons aren't well known for why some dinosaurs got so large.

Interestingly, that article doesn't mention the theory that I think is most promising – that there was potentially a higher concentration of oxygen in the air when the dinosaurs were around, making it easier to get enough oxygen even if you were much larger in size.

I thought that was an accepted fact. It's been a while since I read about dinosaurs : )

My theory is that insects got larger because of the higher oxygen. And then everything else all the way up the food chain had to get bigger too.

Most dinosaurs were herbivores, so I don't think that works.

We’ll consider perhaps the whole carnivore food chain increased in size because the base food source (insects) got bigger.

Any herbivores would also have to increase in size to not get eaten.

In 'our' era, the megafauna of North America were pretty big as well (up until 13ka). Giant sloths, wolves, cats... and they survived an ice age. Not so well-known either.

did NOT expect this to be that interesting for me.

same. I did not think I would even think about this, and now I don't know what I should to with this information, gotta share this with someone