Too much evidence for that, thanks to how many almost complete t. rex skeletons we have + the fact that almost all giant carnivorous dinosaurs had tiny arms. However, there's a non-zero chance they were fluffy in at least some places, and a high chance they were incredibly fluffy as chicks, given how fluffy one of their close relatives is known to be.
Those are cousins. Our closest living relatives are chimps, who are less like us than more distantly related apes. We're the last species of human because we out competed everyone else in one way or another. Rodents are similar to our first ancestors, but not exactly the same.
Basically all mammals in the Old World have had to deal with ancient humans for millions of years. Those humans used tools and dominated ecosystems for a solid chunk of that time. A ton of mammals have probably evolved to be terrified of us specifically. We've been dangerous for a long time.
Now we wield godlike power that far outpaces our intelligence. We're real life eldritch horrors to other animals, bringing apocalypse without even trying. It's hard for us to not cause accidental extinctions by simply inhabiting an area.
When humans first settled the Americas, it was probably an awful experience for most animals living there. Imagine if they saw a femboy with an AR-15 prancing around in a maid outfit without a care in the world. It'd be like encountering Cthulhu.