Evidence for gregarious behavior and age segregation in sauropod dinosaurs

摘要: Abstract Both body fossil and ichnofossil evidence for gregarious behavior in sauropod dinosaurs is examined. Some localities suggest that herds were partitioned on the basis of age, whereas other sites reveal groups consisting both adult juvenile/subadult individuals. Two skeletal accumulations showing age segregation are examined detail. The Mother's Day Quarry Upper Jurassic Morrison Formation Montana contains remains several immature diplodocoid sauropods. An assemblage Cretaceous Javelina Big Bend National Park Texas consists entirely juvenile Alamosaurus. assemblages interpreted here as remnants age-segregated herds. differences between composed animals mixed-age ichnological imply herd composition was variable. When recognized, modern taxa, it thought to minimize fitness costs related behavioral synchronization within social groups. Age also contraindicates extended parental care typical at least some taxa.