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Iberomesornis it was a little, early, toothed bird that lived throughout the early Cretaceous period.

Ice Age it is a time lasting thousands of years in which the Earth is very cold and mostly covered by ice and glaciers.

Ichnogenera groups of dinosaurs whose distinctiveness are surmised only from their fossilized footprints.

Ichnology it is the study of fossilized footprints.

Ichthyornis it means to "fish bird" and it was an 8 inch (20 cm) long, tern-like, extinct bird that lived throughout the late Cretaceous era (135-70 million years ago)

Ichthyosaurs it is a type of Sea-dwelling, prehistoric reptiles. Ichthyosaur means "fish-lizard".

Igneous Rock When molten rock (lava) cools, it is created.

Iguanodon it is the second dinosaur in history ever to receive a name.
Iguanodontids were large, plant-eating, ornithischian ornithopods who lived from the late Jurassic periods to the late Cretaceous periods.

Incisivosaurus This buck-toothed dinosaur was the Cretaceous equal of a beaver.

Indosaurus was a theropod dinosaur from the late Cretaceous era, roughly 70 to 65 million years before.

Indosuchus was a theropod dinosaur from the late Cretaceous era, approximately 70 to 65 million years ago.

Infraorder Suborders are classified addicted to infraorders.

Ingenia it was a bird-like theropod dinosaur, an oviraptorid.

Insects it has exoskeletons and six legs. They evolved throughout the Silurian Period, 438 to 408 mya, long ahead of dinosaurs existed.

Invertebrates are animals exclusive of a backbone.

Isanosaurus was a sauropod dinosaur from the late Triassic era

Ischisaurus was a little, very early theropod dinosaur from the late Triassic era, about 225 million years ago.

Itemirus was a minute, theropod dinosaur from the late Cretaceous era, about 90 million years before.