Amphicoelias
Amphicoelias ( , meaning "biconcave" , from the Greek ἀμφί , "amphi": "on both sides" , and κοῖλος , "koilos": "hollow , concave" ) is a genus of herbivorous sauropod dinosaur that lived approximately 150 million years ago during the Tithonian ( Late Jurassic Period ) of what is now Colorado , United States . 
<triplet> Tithonian <subj> Late Jurassic <obj> part of