During which periods of the late Paleozoic era did the freshwater shark *Xenacanthus* thrive?
Answer
Carboniferous and Permian periods
*Xenacanthus* is chronologically placed within a specific timeframe corresponding to the latter part of the Paleozoic era. The text specifies that this ancient, extinct genus of freshwater shark inhabited the waters primarily during the Carboniferous period and extended its presence into the subsequent Permian period. This time frame is significant as it encompasses the rise and diversification of early tetrapods, with whom *Xenacanthus* would have shared its unique freshwater habitat and competed for resources.
Related Questions
What is the direct translation of the genus name *Xenacanthus*?From which specific anatomical area does the defining nuchal spine of *Xenacanthus* extend backward?Which morphology best describes the overall body shape of *Xenacanthus* compared to modern open-ocean sharks?How does the configuration of the dorsal fins in *Xenacanthus* differ from the familiar shark body plan?What specific structural characteristic defines the dentition of *Xenacanthus*?What specialized ecological niche did *Xenacanthus* occupy during the late Paleozoic era?*Xenacanthus* is the most famous genus within which distinct, extinct order of specialized freshwater sharks?Which posterior locomotor structure was significantly elongated in *Xenacanthus*, suggesting optimization for agility?During which periods of the late Paleozoic era did the freshwater shark *Xenacanthus* thrive?Regarding the cranial details, how were the jaws of *Xenacanthus* situated on the head structure?What is the generally hypothesized primary defensive function attributed to the prominent, sharp nuchal spine?