Was Therizinosaurus a carnivore, herbivore, or omnivore?

Google can be your friend. Apparently they were herbivores, with long necks to out compete for foliage.

Apparently this is real, but my inclination was that this is a made-up hoax

There-is-no-saurus…

Since we didn’t know they existed until 1954, there is some mystery surrounding the full knowledge of them. They were originally thought to be a turtle-like reptile, but that has changed over the years and they have been classified as a herbivore due to their long neck and short forearms. They are now assumed to be a therapod which is a carnivore. The truth is that we have no clue exactly what they were nor how they survived. At the time they were discovered, they were believed to be over 70 million years old and we only discovered them about 68 years ago

This site seems to be a little more official than Wiki & they say close to the same except that they say that there is NO way to know the eating habits for sure since there was no skull when found. They have listed it as a herbivore or possibly a carnivore without ever being able to prove either. The dates differ just a little in that it was discovered in 1948 in Mongolia. Then in 1970, Russian paleontologist Anatoly Konstantinovich Rozhdestvensky insisted that it was a dinosaur & not a turtle-like reptile. That’s when the perception of this creature shifted. Since they haven’t figured it out in my lifetime, I’m going to guess that we might never know!!!