DinosaursFossilsPaleontologyPhylogenyRNA, Ribosomal, 16SDNA, RibosomalAlligators and CrocodilesGenes, rRNAReptilesSkeletonAnatomy, ComparativeSequence Analysis, DNABiological EvolutionExtinction, BiologicalGeological ProcessesDNA, BacterialMolecular Sequence DataSkullBody SizeBirdsStruthioniformesCarnivoryMontanaEgg ShellFeathersToothGeological PhenomenaGeologyPaleodontologyBone and BonesHumerusHorns