LOCALITY:
Gobi Desert, Southern MongoliaAGE:
Late Cretaceous (Late Campanian-Early Maastrichtian),
Nemegt Formation, 70 million years ago
SIZE:
Therizinosaurus arms were about 2.5 metres long,
scythe-like claw 70cm long around its outer curve
Deinocheirus arms about 2.6 metres long
MEANING OF NAME:
Therizinosaurus 'Scythe reptile
Deinocheirus, 'Terrible hand'
'PRONUNCIATION:
Ther-ih-sen-oh-SAWR-us;Dine-oh-KIR-us
CLASSIFICATION:
THEROPODA: relationships uncertain
For many years Therizinosaurus
cheloniformis and Deinocheirus mirificus
presented palaeontologists with a puzzle. Evidently
somehow related to the theropods or carnivorous
dinosaurs, the function of their large claws and their
attendant forelimbs was a mystery. Certainly, they had to
belong to animals quite unlike Tarbosaurus bataar
with its highly reduced forelimbs and yet they were
animals clearly in the same size category.
Material that has recently come to
light in China suggests that these animals were as
atypical of large carnivorous dinosaurs as pandas are
atypical of bears. Like pandas, they were probably gentle
herbivores. They used their large forelimbs and claws to
pull down branches on which to browse. The claws with the
horny sheath that would have fitted over the outside of
the bone may have been up to one metre long.
Some palaeontologists have even
suggested that therizinosaurs may have used the
huge claws for ripping into ant nests.
The picture of Therizinosaurus
cheloniformis and Deinocheirus mirificus as
browsers in a forest agrees well with the view that
conditions in Central Asia had become much moremoist than
what they had been like 10 million years before these
dinosaurs lived.
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