Xenacanthus is a genus of prehistoric sharks. The first species of the genus lived in the Late Devonian, the genus surviving until the end of the Triassic, over 200 million years ago. Fossils of various species have been found worldwide. The species identified at Petrified Forest National Park is X. moorei.
Did You Know?
Petroglyphs are sometimes calendars, marking events like the summer solstice with interactions between the glyph, the sun, and natural landscape features.