An international team of paleontologists has announced a breakthrough fossil find that answers a long-standing question relevant to the origins of all modern birds. The research team found a new velociraptorine fossil, Shri rapax. This extraordinary discovery preserved a beast with exceptionally gigantic and muscular clawed hands. This finding indicates a unique predatory niche in Mongolia’s Late Cretaceous desert fauna. Results from this research were recently published in the journal Historical Biology.
What makes Shri rapax particularly remarkable is its almost full skeleton. This skeleton, pieced together from multiple individuals, provided wonderful clues about this creature’s anatomy, locomotion, and ecology. In 2016, scientists from the Royal Belgian Institute of Natural Sciences (RBINS) isolated and CT scanned the fossil’s skull and the first four cervical vertebrae. Analysis of this process pointed out its peculiarity, separating it from other members of the Velociraptorinae subfamily.
Unique Anatomical Features
The morphological analysis of Shri rapax revealed a host of impressive anatomical features that suggest an impressive predatory ability. Remarkably, its large increased hand structure suggests that it would be able to generate prey handling forces greater than those estimated for Velociraptor 20. This adaptation for evolution suggests that Shri rapax was highly adapted for predation on considerably larger prey. It was probably feeding on adult protoceratopsians or juvenile ankylosaurs!
At least from the size of their skulls, Shri rapax seems to have had a stronger bite. This formidable jaw configuration would have greatly assisted it in biting and eating more resilient prey items. Morphometric and cladistic analyses found Shri rapax a sister species to Shri devi from the Baruungoyot formation. This shared feature is significant as it indicates a close evolutionary relationship between the two dinosaurs.
“A new bird-like dinosaur from the Upper Cretaceous of Mongolia with extremely robust hands supports niche partitioning among velociraptorines.” – Léa Moutrille et al.
In total, researchers found ten post-cranial traits in Shri rapax that differed from those of Shri devi. These features include a unique 135° opisthopubic pubis and an ischium that measures 66% the length of its pubis. Moreover, the lack of an ischial tuberosity further sets this species apart, stressing its special adaptations to life in trees.
A Troubled Provenance
The provenance of the Shri rapax specimen has raised eyebrows in the scientific community, mainly due to the shady nature of black market poaching. Researchers suspect the fossil was already damaged prior to 2010. This deeply complicates its recovery history as well as raises significant ethical questions about its study. From the French company Eldonia, the nearly complete skeleton features 23 tail vertebrae, an intact manus, and most major girdle elements. As of 2019, it has been repatriated to Mongolia.
This situation underscores the ongoing challenges faced by paleontologists in accessing and studying fossils that may have been illegally traded or mishandled. The recovery of such specimens is ever more important to help elucidate the evolutionary history of prehistoric life.
Insights into Ecosystem Dynamics
The paleobiological importance of the discovery of Shri rapax lies in the light it sheds on predator-prey dynamics within its ecosystem. Its paws are huge and powerful, and its jaws are even more massively built. These features suggest that it filled a distinctive ecological niche within the velociraptorines. Its adaptations indicate a specialization for pursuit of larger prey. This unique ability probably allowed it to get along with other carnivorous dinosaurs around it, as well as avoiding a competition for food resources.
Shri rapax makes its debut in Mongolia’s Late Cretaceous desert fauna. This landmark discovery suggests that dinosaur diversity at the time was richer and more complicated than we’ve long thought. These interesting evolutionary adaptations enhance our knowledge of velociraptorines. They provide us an invaluable insight into how these remarkable animals lived, behaved, adapted, and thrived in their environments.
