Or simply less numerous. We do know that many of us (Europeans and Asians) have some Neanderthal DNA, it's entirely possible they were just bred out of existence.

According to 21andMe, I am a whopping 3% neanderthal.

Don't know why I felt compelled to share this here, alas, there you go.

That's 23andme. I also have a high Neanderthal percentage.

Wikipedia says modern humans have somewhere between 1% and 4%.

https://en.wikipedia.org/wiki/Neanderthal#Genome

Right on, something seemed off in the name but I just didn't look it up. Should have known too, 23x2=56.

Most Asian and European people have neanderthal DNA.

I didn't say that we are smarter.

However, a smaller brain might have been better at that time. For example, a bigger brain requires more energy.

On the other hand, death in childbirth was a major hazard for females. Although I think Neanderthals' brain size at childbirth was similar to that of modern-day babies - but later it grew faster.

One has to wonder: if there were ever any other intelligent species (that we couldn't breed with) on this planet alongside us, then we probably wiped them out..

Why would we necessarily be what wiped them out? Intelligent dinosaurs may have been wiped out by an asteroid/volcanic activity/climate disruption (or whatever the most current theory is).

While they werent dumb lizards, i havent heard anyone claim dinos were dolphin or ape-smart. The brains were small and structured very differently than animals we today consider smart.

Bird brains are also very different from mammal brains, yet corvids are considered to be one of the smartest species.

Edited it a bit. :)

Were humans around at the time of the dinosaur extinction event?

idiocracy