Segnosaurus

Segnosaurus is a genus of theropod dinosaur belonging to the group Therizinosauria, known from the Late Cretaceous of Asia, with fossils recovered from Mongolia's Gobi Desert in formations such as Nemegt. The available material indicates it lived during the later part of the Cretaceous, a time when therizinosaurs were diversifying in Asia.

Discovery and material while incomplete, Segnosaurus is documented from fragmentary postcranial remains found in Mongolian deposits. The known fossils are primarily piece(s) of the pelvis and hind limbs, and skull material, if present, is rare or not well described. As a result, our understanding of its precise appearance and full range of motion remains limited. Despite the fragmentary record, Segnosaurus is recognized as a member of Therizinosauria, a group of unusual theropods.

Anatomy and ecology therizinosaurs are characterized by elongated arms ending in large claws, a broad pelvis, and often a beaked mouth. While specific details for Segnosaurus are constrained by available material, it would be expected to share the general therizinosaurian body plan, including robust forelimbs and adaptations interpreted as associated with a herbivorous or omnivorous diet. This contrasts with the more typical carnivorous morphology of many other theropods.

Taxonomic and paleobiological significance Segnosaurus occupies a position within Therizinosauria that helps illustrate the early diversification of this lineage in Asia. Its remains contribute to understanding the evolution of therizinosaurs and their geographic distribution, particularly in the Late Cretaceous ecosystem of the Mongolian Gobi.