The Yellowstone Caldera is not alone. Many older remains of similar calderas can be found arranged in a row west of the presently active one. But there is something more about it.
Besides the calderas, fissure svarms and the Nevada Rift Zone are found north and south of the track. https://www.usgs.gov/observatories/yvo/news/just-how-long-has-yellowstone-hotspot-been-around?qt-news_science_products=4. These extra volcanic features are about 17 million years old, and show resemblance with the convection rolls presumed to be found underneath. The convection rolls theory can also explain the long features associated with the caldera. In Iceland, there are many volcanic systems combined of a caldera with fissures extending from it to the north and south. Another analogy is the fact that the Emeror Chain, considered to be a part of the Havaii Chain, actually formed along a north-south aligned line, with volcanic activity propagating south until it reached the latitude of the present Hawaii hotspot. Therefore, the hot spots, such as Yellowstone and Hawaii, are actually short sections of ´hot lines´, extending secretly north and south of them, underneath the tectonic plates.