A Time Capsule!
Explanation
The Joke
A group of people discover a time capsule from the past. As they open it, they find various artifacts and explain them to each other. One item is identified as "a T. Rex femur" -- they note that people "used to attack a lot, but we were tougher back then." Another item is "a woodprime" that "people used to use to read on paper." They also find "a brain-chip" that "they put these in kids so they'd grow up as mega-geniuses," to which someone responds with awe. One person admits "I got this right before they ran out of them."
The final panel reveals a person asking "Hey, what were you digging at 3AM last night?" suggesting the "time capsule" is actually just a buried box of random junk that someone buried recently and is passing off as an ancient artifact, trying to impress people. The response is simply: "Respect."
The Humor
The comic works by initially presenting what appears to be a far-future scenario where people are examining artifacts from our time (or earlier). The items found are increasingly absurd -- a dinosaur bone, a mysterious "woodprime," and brain-enhancing chips. The humor builds as the descriptions of these items become more and more outlandish, and the listeners become more and more impressed.
The punchline pulls the rug out: someone saw the person digging at 3 AM, implying they just buried this box of random items and are pretending it's an ancient time capsule to seem impressive and smart. The final "Respect" acknowledges the audacity of the con while also finding it genuinely admirable in a way. The comic satirizes how easily people can be impressed by mysterious-sounding artifacts and pseudo-historical claims.