They include : Ceratopsia Hadrosauridae Ankylosauria Hypsilophodontidae Pachycephalosauria Tyrannosauridae Ornithomimidae Caenagnathidae Dromaeosauridae Troodontidae Classification Uncertain Birds such as Hesperornithiformes were present , as well as giant Pterosauria related to Quetzalcoatlus .
They include : Ceratopsia Hadrosauridae Ankylosauria Hypsilophodontidae Pachycephalosauria Tyrannosauridae Ornithomimidae Caenagnathidae Dromaeosauridae Troodontidae Classification Uncertain Birds of the Hesperornis type were present , as well as giant Pterosauria related to Quetzalcoatlus .