The jaguar was originally native to Texas, as was the jaguarundi. There was a lot of varmint-shooting of them in the 19th & early 20th centuries, but there were still some around as late as the '30s. I think what probably drove them out was a combination of varmint-shooting & the Texas Fever cattle dipping from the 1870s to the 1950s. A lot of arsenic got spread around during that period--the dip contained 8 lbs of powdered white arsenic to every 500 gal of water--& as a result a lot of critters either died out or were chased out.
I've never personally seen a black cougar, just that hide back in the '50s. I have, however, personally seen 2 black bears in Palo Pinto County, Texas.
The first one was just off old US 80 just west of Palo Pinto. The road goes down the hill there normally now, but there were, back in the '70s, remnants of the old Model T era switchback road. There were a lot of grapevines hanging over that old road. The first bear I saw there was standing on its hind legs, pushing bunches of mustang grapes into its mouth with a forepaw. Folks tried to tell me I'd seen a feral hog, but I've seen a lot of feral hogs. I've never seen one stand up on its hind legs & use a front hoof to put food in its mouth.
The second one I saw on a creek feeding into Palo Pinto Lake. I was in a deer stand, glassing the water's edge, when I saw a half-grown bear come down to the water. I thought it was going to drink, but instead it was intending to play. It would slap the water with a forepaw & bite at the drops it splashed up. I watched that thing for half an hour doing that. I may have missed every trophy buck in Palo Pinto County, but I wouldn't trade watching that little bear for anything.