The animals may disagree.
Ask them.
A simple container? Like a large leaf for collecting things, a hollow tree branch, an animal hide, etc.
Wouldn’t wheels be older? Fire? 
Okay, moving forward in time a little. What’s the longest-lived machine?
This is a what I thought.
Sling, maybe.
Rollers, if you are willing to count them.
Language. Amazing technology, still in use today. The foundation of everything else we do. So successful that Godott himself tried to Babel us down with a tower. As so often, he only made matters worse.
Aw, man. I forgot about simple machines.
Yeah, it’s a slippery slope.
How about bow and arrow? Does that predate the wheeled cart?
Not really. I count a suitable stone to crack open nuts or shellfish as a hammer, and this use surely predates the controlled use of fire, let alone the wheel which was only invented a few thousand years ago.
I’d thought wheels were around longer than that. Fair point about stones as hammers, though. When I saw “hammer”, my mind went to the metal toolbox object. Didn’t consider different shapes filling the same function.
Yeah, It’s somewhat surprising how long it took mankind to invent the wheel. The New World didn’t have it until Columbus arrived, and they got along just fine.
Slippery slopes are an ancient technology.
I would argue for grinding wheel or the cart. The wheel itself doesn’t serve a purpose without an application.
A mechanism is more of a technology than a simple tool or container.
That’s another good contender. Hard to tell whether that or the modified stick came first. I think chimps use chewed and waddled up leaves to soak up water, too; and in neither case are there going to be recognizable fossils.