What major geological event led to the geographic isolation favoring abelisaurid evolution?
Answer
Breakup of Gondwana
The evolutionary trajectory of *Xenotarsosaurus* and the success of the entire Abelisauridae family are intrinsically linked to major tectonic shifts during the Mesozoic Era. Specifically, the continued fracturing and breakup of the supercontinent Gondwana caused the dinosaur faunas of South America to become geographically isolated from the faunas evolving on the northern continents, which were remnants of Laurasia. This isolation meant that South American ecosystems developed unique evolutionary pathways, allowing abelisaurids to evolve into the dominant apex predators in that region, filling the ecological niche that tyrannosaurs occupied elsewhere.
Related Questions
What does the genus name *Xenotarsosaurus* translate to?In which geological unit were the remains defining *Xenotarsosaurus* unearthed?Which dinosaur family does *Xenotarsosaurus* firmly belong to?What evolutionary concept explains the apex predator role of Abelisaurids in isolated Gondwanan remnants?How do Abelisaurid skulls, including that of *Xenotarsosaurus*, generally compare to Tyrannosaurid skulls?Who is specifically honored by the specific epithet *bonapartei*?What unusual skeletal structure gave *Xenotarsosaurus* its descriptive genus name?What major geological event led to the geographic isolation favoring abelisaurid evolution?Compared to Tyrannosaurids, what characterizes the forelimbs of Abelisaurids like *Xenotarsosaurus*?What characteristic of the ancient Chubut environment might have influenced the specialized tarsus of *Xenotarsosaurus*?