Larry Niven's "Eye of an Octopus": Humans dig up a Martian's grave

The plot is so fantastic & far fetched. And yet a very readable story.

Story summary.
Three early human explorers on Mars. Henry Bedrosian & Christopher Luden go down to the surface; Abe Cooper is in orbit.

Henry & Chris find a well near the landing site - very similar to wells on earth! And something is written there in an unfamiliar script! But it's boundary wall appears to be of some unfamiliar material. Attempts to break a piece of wall for analysis results in serious damage to hammer rather than wall! A little later, we find the wall is made from solid diamond!

Analysis of a sample of well's contents shows it's very dilute nitric acid. Soon, they discover a kind of well preserved mummy near well - of a Martian supposedly sentient. And he appears to have been buried for only for a few hundreds or thousands of years - means others should be nearby - though we will not see them!

And the Martian is very hominid. They also find a buried contraption that is almost certainly a variant of a bicycle! Title of the story is to explain why he is a hominid & why the aliens made a bicycle. We are told octopus eyes are very similar to human eyes - even though the two have very different evolution lines. By implication, you should expect smart sentients to be hominids.

Anyway, while carrying the body of local back to ship, there is an accident. Apparently, his local chemistry is such that a contact with water will result in a blast. Our two explorers barely escape.

Fact sheet.
"Eye of an Octopus", short story, review
First published: Galaxy, February 1966
Rating: B
Series: "Eye of an Octopus", "How the Heros Die" (A), "At the Bottom of a Hole" (B).