Tianyuraptor also differs from previously known dromaeosaurids in that it possesses a relatively small furcula ("wishbone"), and unusually short forelimbs.

The specific epithet, ostromi, is in honor of John Ostrom,[1] who contributed greatly to the study of dromaeosaurid fossils, including Deinonychus and feathered dinosaurs.

The fossil was discovered in the Dawangzhangzi Bed of the Yixian Formation (Jehol Group), located in Lingyuan in western Liaoning, China.

[1] The Yixian Formation is an Early Cretaceous rock unit, dated to between approximately 129.7 and 122.1 million years old, in the Barremian and Aptian faunal stages.

[8] Aside from elongate hind limbs, Tianyuraptor is different from other members of Microraptorinae in regards to the relative lengths of the forelimb elements.

However, the shortened forelimbs, small furcula, and the transversely wide coracoid in Tianyuraptor suggest that it was not suited for aerodynamic gliding or flight.

A phylogenetic analysis performed by Zheng et al. showed Tianyuraptor to be a basal member of a group containing Laurasian dromaeosaurids.

However, it is also equally possible, as argued by Zheng et al., that Tianyuraptor may in fact be a basal member of a clade containing all other Laurasian dromaeosaurids with the exception of Microraptorinae.