Shop for educational dinosaur skeletons, skulls, fossils, claws, toes, fingers, teeth or tooth replicas. These elements make wonderful gifts for everyone who loves dinosaurs. A lot of our customers use these very replicas to decorate professional offices. These models are all of museum quality and made of resin and acrylic, which gives them such realistic appearances. They first appeared during the Triassic period, 231.4 million years ago, and were the dominant terrestrial vertebrates for 135 million years, from the beginning of the Jurassic about 201 million years ago until the end of the Cretaceous – 66 million years ago, when the Cretaceous Paleogene extinction event led to the extinction of most dinosaur groups at the close of the Mesozoic Era. The fossil record indicates that birds evolved from theropod dinosaurs during the Jurassic Period and, consequently, they are considered a subgroup of dinosaurs by many paleontologists.