Kinnareemimus (/ˌkɪnəriˈmɑːiməs/, meaning "Kinnaree mimic", after a figure from Thai folklore) is an extinct genus of ornithomimosaurian theropod dinosaur that was discovered in the Early Cretaceous Sao Khua Formation in what is now Thailand.

[1] Ornithomimosaur body fossils and ichnofossils were reported in Thailand's Khorat Plateau as early as 1997 in a publication by Eric Buffetaut and colleagues.

[3] In this publication, the taxon is referred to by the nomen nudum "Ginnareemimus" by Ryuichi Kaneko, who wrote an article in the magazine which contained recent information about paleontology in Thailand.

[4][5] Kinnareemimus received a formal species description in 2009 when Eric Buffetaut, Varavudh Suteethorn, and Haiyan Tong published an anatomical monograph in the bulletin of the Geological Society of London.

All the bones referable to ornithomimosaurs found at Phu Wiang 5 were disarticulated, and it is therefore impossible to know exactly how many individual animals were fossilized at the site.

[1] When it was described, the authors named the genus after Kinnaree, a being from the folklore of the Thai people which has the head and torso of a woman and the legs of a bird and lives in the legendary Himmapan Forest.

[1] Because the holotype of Kinnareemimus is so fragmentary (consisting of only a single metatarsal), estimates of the animal's size have always been highly speculative and uncertain.

The authors describing it believe it may have belonged to the same individual, and so they used it to estimate a full-length of the third metatarsal to have been roughly 145 millimetres (5.7 in) in life.

[1] This specimen was used to diagnose Kinnareemimus as distinct from all other ornithomimosaurs based on the following apomorphies: a semi-arctometatarsalian condition where the third metatarsal is still visible in proximal view and which narrows in the distal direction before flaring into a wider triangular cross-section at the distal-most end.

[1] This diagnosis was amended in 2024 by Samathi to include ventrally-flattened pedal unguals with flexor fossae, which supported the inclusion of Kinnareemimus within ornithomimosauria.

The seven vertebrae preserved from other parts of the tail display varying degrees of fusion, indicating these specimens are from a multi-age assemblage.

The single partial toe claw that is preserved lacks a flexor tubercle, analogous to the third ungual in Struthiomimus.

To address the uncertainty in the literature up until this point, Samathi scored the anatomical data for Kinnareemimus within three independent theropod matrices.

The matrix from Choiniere and colleagues, which was also modified by Samathi to include Deinocheirus, recovered Kinnareemimus as a basal member of Deinocheiridae.

The estimated length of the tarsus in Kinnareemimus was comparable to the known remains of Garudimimus, and was substantially smaller than the ratios known from Struthiomimus and Gallimimus, which are believed to have been well-adapted for running.

[1] However, the authors also remarked that the metatarsals of Kinnareemimus were much more slender than those of the closely-related Archaeornithomimus, which may suggest that either the animal was not fully grown, or it may have acquired paedomorphic traits.

[12] There have historically been reports of ichthyosaur and plesiosaur teeth from the Sao Khua Formation, but these have now been identified as belonging to crocodyliformes, which are mostly non-marine during the Cretaceous.

[13][14] The sediments of the Sao Khua Formation are composed of red clays, mudstones, sandstones, siltstones, and conglomerate rocks, which indicate a fluvial environment which also possessed lakes, floodplains, and braided channels.

These include the neosuchians Siamosuchus, Sunosuchus, and Theriosuchus, numerous species of turtles, amiiform fish, several hybodontiform sharks, and freshwater bivalves.