Columbia Encyclopedia

(Encyclopedia) reptile, name for the dry-skinned, usually scaly, cold-blooded vertebrates (see Chordata) of the order Reptilia. Reptiles are found in a variety of habitats throughout the warm and temperate regions (...

(Encyclopedia) mass extinction, the extinction of a large percentage of the earth's species, opening ecological niches for other species to fill. There have been at least ten such events. The five greatest were thos...

(Encyclopedia)  CE5 Colorado kŏlərădˈə, –rădˈō, –räˈdō [key], state, W central United States, one of the Rocky Mt. states. It is bordered by Wyoming (N), Nebraska (N, E), Kansas (E), Oklahoma and Ne...

(Encyclopedia)  CE5 Utah yo͞oˈtäˌ [key], Rocky Mt. state of the W United States. It is bordered by Idaho and Wyoming (N), Colorado (E), Arizona (S), and Nevada (W), and touches New Mexico in the SE, at the Fou...

(Encyclopedia)  CE5 Common features in representative groups of the phylum Chordata Chordata kôrdāˈtə, –däˈ– [key], phylum of animals having a notochord, or dorsal stiffening rod, as the chief internal ...

(Encyclopedia)  National Parks and Monuments 1 National Parks and Monuments National Monuments National and International Historic Sites and Historical Parks National Memorials National Battlef...