The Djadochta Formation is separated into a lower Bayn Dzak Member and upper Turgrugyin Member. V. mongoliensis is known from both members, represented by numerous specimens. The Bayn Dzak Member (mainly Bayn Dzak locality) has yielded the oviraptorid Oviraptor; ankylosaurid Pinacosaurus grangeri; protoceratopsid Protoceratops andrewsi; and troodontid Saurornithoides. The younger Turgrugyin Member (mainly Tugriken Shireh locality) has produced the bird Elsornis; dromaeosaurid Mahakala: ornithomimid Aepyornithomimus; and protoceratopsid Protoceratops andrewsi.
The Djadochta Formation is separated into a lower Bayn Dzak Member and upper Turgrugyin Member. V. mongoliensis is known from both members, represented by numerous specimens. The Bayn Dzak Member (mainly Bayn Dzak locality) has yielded the oviraptorid Oviraptor; ankylosaurid Pinacosaurus grangeri; protoceratopsid Protoceratops andrewsi; and troodontid Saurornithoides. The younger Turgrugyin Member (mainly Tugriken Shireh locality) has produced the bird Elsornis; dromaeosaurid Mahakala: ornithomimid Aepyornithomimus; and protoceratopsid Protoceratops andrewsi.