Sci fi story - "The Great Mutation"?

[zyx]

Trying to find out the name/author of a story my teacher read to us in school (and let's just say this was a few decades ago!) The story was set in the distant future where a father is taking his young son around a zoo. The father talks about a "Great Mutation" that affected life on Earth many years ago, and the animals in the zoo are weird creatures like a cross between a bear and a sabre-toothed tiger, etc. The boy makes the mistake of sticking his hand in the cage and the creature bites it off. Later in the hospital the punchline is when the doctor says to the father: "Well, look on the bright side, sir. Your son still has three good arms!"

(I tried Googling "Great Mutation" but it is not the Talmage Powell story by that name.)

[Dr Strange]

"Zoo 2000" by Richard Curtis, from a 1973 anthology of the same name edited by Jane Yolen.

Cover - 

 

There is a pdf scan of the story from a different source (some sort of English teaching textbook, I think) here -

1.cdn.edl.io/CqvkES32sr726crcDymH4UyG0cFqC6wfLqSceru5S7atNhVa.pdf

[zyx]

Yes, that's the one, thank you! I just found the whole book on the Internet Archive.

My strongest memory is that after our teacher finished reading the story, she asked the class "Now, what was odd about that story?" One kid put up his hand and said quite seriously "That the boy survived the attack." The rest of the class groaned...