Therizinosaurus Fink
Life restoration of Therizinosaurus by Stanton Fink
Vital statistics
Scientific Name Therizinosaurus
Length 33 feet
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Weight {{{weight}}}
Diet Probably herbivorous
Lived Late Cretaceous 75 million years ago
Range {{{location}}}
Therizinosaurus ("scythe lizard") was a therizinosaurid dinosaur from the Late Cretaceous Period of Mongolia.


The fossil remains of Therizinosaurus are incomplete, so it is difficult to reconstruct the dinosaur from this material alone. However, better fossils of other therizinosaurs are known, so it is possible to make inferences based on the remains of other genera. As such, Therizinosaurus likely had a small head and long neck set upon a heavy body and short legs. It may have reached lengths of 10 meters and may have weighed 5 tonnes.[1]

The forelimbs of Therizinosaurus are known, and they may have reached a maximum length of nearly 3 meters. Their most noticeable feature was the three gigantic claws on each hand, which inspired the animal's name (which translates to "scythe lizard"). Each claw was a meter long or more, the longest known claws of any animal.[2]


Therizinosaurus belongs to the family Therizinosauridae, which was originally created specifically for this genus. The cladogram below shows the position of Therizinosaurus within the family based on a 2007 study.[3]









The claws of Therizinosaurus were first discovered in 1948 during a joint Soviet-Mongolian expedition in the Nemegt Formation.[4] They were named and described in 1954 as Therizinosaurus cheloniformis by Russian paleontologist Evgeny Maleev, who thought they belonged to a large and aquatic turtle-like creature.[2] In 1970 the claws were determined to belong to a type of theropod dinosaur,[5] but because the remains were so incomplete it was impossible to tell exactly what kind of theropod it was.

However, more fossil remains were collected in the 1970s and 1980s,[6] and related dinosaurs from China were discovered. It was also discovered that the dinosaurs of the segnosaurid family were in fact therizinosaurs, allowing paleontologists to more accurately reconstruct Therizinosaurus based on its newly determined close relatives.



Unlike many other groups of theropod dinosaur but similar to other therizinosaurids, Therizinosaurus was probably herbivorous.[7]

In popular cultureEdit

The strange claws of Therizinosaurus were appealing to a wide audience, and since it has been more confidently reconstructed it has appeared in television documentaries such as Chased by Dinosaurs and video games such as Dino Crisis.


  1. Paul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press p. 160
  2. 2.0 2.1 Maleev, E.A. (1954). "New turtle−like reptile in Mongolia [in Russian]." Priroda, 1954(3): 106–108.
  3. Senter, P. (2007). "A new look at the phylogeny of Coelurosauria (Dinosauria: Theropoda)." Journal of Systematic Palaeontology, (doi:10.1017/S1477201907002143).
  4. Barsbold, R. (1983). "Carnivorous dinosaurs from the Cretaceous of Mongolia [in Russian]." Trudy, Sovmestnaâ Sovetsko−Mongol’skaâ paleontologičeskaâ èkspediciâ, 19: 1–120.
  5. Rozhdestvensky, A.K. (1970). "On the gigantic claws of mysterious Mesozoic reptiles." Paleontologischeskii Zhurnal, 1970(1): 131-141.
  6. Perle, A., 1982, "On a new finding of the hindlimb of Therizinosaurus sp. from the Late Cretaceous of Mongolia", Problems on the Geology of Mongolia, 5: 94–98
  7. Svarney, T.E. and Svarney, P.B. (2003). "The Handy Dinosaur Answer Book", 1st ed. Canton, MI: Visible Ink Press.