Many say that Yertle the Turtle by Dr. Seuss was banned for reasons of early marxism. Is that true?
The title appears to be Yertle the Turtle. It's about authoritarianism and its failures, not Marxism. It might have been banned in some places in the USA, because it used the word "burp," considered somewhat rude in 1958, but it sold well.
There's a reasonably well-known turtle called Myrtle at the New England Aquarium, but she's only been there since 1970. Mind you, it's a pretty obvious name for any female turtle.