Analysis of the structure of the 30cm-long fossilised hip (pubis) bone led to identifying the owner as a:
- tyrant lizard - tyrannosauroid
- tyrannosaurids and ancestor of Tyranosaurus rex
Structural features shared with tyrannosauroids:
- Several distinctive synapomorphies indicate tyrannosauroid affinities
- transversely narrow, parallel-sided pubic boot indicates referral to Coelurosauria
- The pubic boot is large; its anteroposterior length is 0.45 times the pubic shaft length (a minimum estimate because the boot is broken).is comparable to those of tyrannosauroids and some basal coelurosaurs
- This demonstrates that advanced tyrannosauroids with characteristic short arms and powerful jaws achieved a global distribution in the Early Cretaceous
Derived features shared with tyrannosaurids, specifically:
- The pubis is almost identical to those of tyrannosaurids
- The pubic tubercle is broken, but the preserved portion indicates a prominent, anterolaterally curving, flangelike morphology
- The anterior expansion of the boot is substantial, as in tyrannosaurids
- The length of NMVP186046 (307 mm) is only slightly longer than the pubis of Raptorex
The features features of the hip bone shared with tyrannosauroids and tyrannosaurid hip bones suggests a potentially cosmopolitan grade of small tyrannosauroids with a tyrannosaurid-like body plan preceded the Late Cretaceous rise of the colossal tyrannosaurids.