Argentina Neuquen Basin Cretaceous 116 South America 95 Neuquén Basin 77 Jurassic 70 biostratigraphy 68 Ammonoidea 55 taxonomy 55 ammonite 50 Bivalvia 47 Mendoza 45 paleoenvironment 45 Andes 38 Hauterivian 35 Biostratigraphy 34 paleoecology 33 Neuquén basin 32 bivalve 32 Tithonian 30 taphonomy 30 Jurassic-Cretaceous boundary 29 Valanginian 29 fossil record 29 carbonate ramp 28 Gastropoda 27 facies analysis 26 Ammonites 23 Anthozoa 21 ichnology 21