As one travels south across the Americas, one notes an obvious change in fauna from the Eurasian therizinosaurs to the 'advanced' hadrosaurids, and finally to these viriosaurs, bipedal ornithopods that have migrated from South America.  Thus, while the bogs of Canada harbor liandaolong, the swamps of warmer America are home to sludgers, and the bayoues of southern and Central America are the domain of the cranili.

    The long-necked, bottom-heavy cranil form is ubiquitous in the marshy areas of central and South America.  The common (or striped) cranil (Kranilis russelae) ranges across Central America, with vagrants reletively common in the brakish swamps of southern North America.  Cranili eat a variety of riperine vegitation and (during times of drought) will venture from the water to strip small trees of their leaves.