Sapience Before People

People have often (almost always) thought that they were the only species to have ever evolve true sapiens, making tools, domesticate other animals, etc. But have there been other truly sapient animals before humans even existed? Here, we speculate on what species may have ruled Earth in their own civilizations long before humans have civilization and even long before humans evolved.

Scenario 1: Pachycephalosaurs
When it comes to prehistoric life, dinosaurs were the most famous of the prehistoric animals. But there is one group of dinosaurs that is often overshadowed by the more famous Tyrannosaurus rex and Triceratops, and that group of dinosaurs was the Pachycephalosaurs. For many decades, people have long thought that Pachycephalosaurs with high-domed heads including Stegoceras were simply just head-butting herbivores much like modern sheep, goats, and muskoxen. However, some scientists have noted that Pachycephalosaurs wouldn't sustain trauma from head-butting, so why did Pachycephalosaurs of several species had them? No one knows for sure, they could only speculate.

66 million years ago
A lone male Triceratops has gotten left behind by his herd. He limps in agony, not from a Tyrannosaurus rex attack, but due to something that has to do with a long stick punctured through is ribs, but what the Triceratops didn't know was that the stick was actually a weaponized tool made of sticks with a sharp stone at the end made by a strange-looking yet-intelligent dinosaur. As the Triceratops heard the rustling in several bushes, he remained cautious for a while, until out of nowhere, another one of those weaponized tools flew right at the Triceratops and struck him in the throat, causing further pain and injuries to hit him hard until he collapsed. The last thing he saw was a group of small fluffy dinosaurs holding weaponized tools in their feet like modern parrots holding objects, and his eyes closed and he was gone. Those small omnivorous intelligent dinosaurs are Pachycephalosaurus, who have hunted this Triceratops with brains and their weaponized tools known as spears, the first of their kind long before humans made spears, in order to feed their tribe. They used their sharp and strong stone tools in order to cut the meat apart before feasting on the flesh. However, unaware of their surroundings, another tribe of Pachycephalosaurs of a different species, slightly smarter despite being smaller, were watching them, Stegoceras. The Stegoceras tribe have ambushed the Pachycephalosaurus tribe, launching out an all-out-war as both tribes fight to keep the Triceratops carcass. But just as the Pachycephalosaurus tribe was winning, the tribe is outnumbered as more Stegoceras surrounded them and the Pachycephalosaurus tribe has retreated, and the Stegoceras tribe have won the prize as they begin their feast on the carcass.