Kiyacursor

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Kiyacursor is an extinct noasaurid theropod dinosaur from the Early Cretaceous of Russia. It is known from a single species, Kiyacursor longipes, and is the first Early Cretaceous ceratosaur discovered in Asia. The holotype, KOKM 5542, was found in 2023 in the Ilek Formation near the Kiya River in Kemerovo Oblast. The partial skeleton includes neck and tail vertebrae, cervical and dorsal ribs, a left shoulder blade, upper arm bones, and much of both hind limbs. A partial neck vertebra, PIN 329/16, found at the same site, may belong to the same individual.

Kiyacursor means “Kiya River runner” and longipes means “long foot.” It is estimated to be about 2.5 meters (8.2 feet) long. Bone histology suggests the holotype was a subadult at death, likely around three years old or more, meaning it would have grown larger as an adult. A notable feature is its large third metatarsal and a reduced second metatarsal, a combination also seen in Elaphrosaurus, Limusaurus, and ostriches, suggesting Kiyacursor was capable of fast running.

In phylogenetic analyses, Kiyacursor sits with other early noasaurids, including Afromimus and an unnamed Australian specimen, forming part of a group related to Noasaurinae and Elaphrosaurinae.

The Ilek Formation, dating to the Aptian stage of the Early Cretaceous, has yielded other dinosaurs such as Psittacosaurus sibiricus (an early ceratopsian) and Sibirotitan (a sauropod), as well as birds like Evgenavis and Mystiornis. The formation also preserves pterosaurs, crocodylomorphs, turtles, lizards, and various synapsids and amphibians, indicating Siberia at the time was a refugium for several relict groups.