Ecosystems

No! After the dinosaurs died out, nearly 65 million years passed before people appeared on Earth. However, small mammals (including shrew-sized primates) were alive at the time of the dinosaurs. Many scientists who study dinosaurs (vertebrate...
Mineral elements provide the color in fireworks. Barium produces bright greens; strontium yields deep reds; copper produces blues; and sodium yields yellow. Other colors can be made my mixing elements; strontium and sodium produce brilliant orange;...
Approximately 700 species have been named. However, a recent scientific review suggests that only about half of these are based on fairly complete specimens that can be shown to be unique and separate species. Also, even if all of the roughly 700...
Forest Visitor Maps are at a smaller scale than USGS topographic quadrangle maps and typically do not show contours. Forest Visitor maps contain general recreational information about things such as camping, fishing, biking, other activities, points of...
A naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties.  
The largest complete dinosaur we know of was Brachiosaurus ('arm lizard'); it reached 23 m in length and 12 m in height (about the length of two large school buses and the height of a four-story building). Fragmentary leg bones and vertebrae of even...
A number of Burmese pythons have been found on Key Largo, and a few in the Lower Keys.  However, there is as yet no evidence of a breeding population anywhere in the Keys.  Because pythons regularly escape or are released from captivity, it can be...
Cicadas are not harmful to humans and they rarely cause significant plant damage. However, the eggs are laid in slits in twigs, so during large emergences of periodical cicadas they can cause substantial damage to branches of trees and shrubs.  
No, salmon are not endangered world-wide. For example, most populations in Alaska are healthy. Some populations in the Pacific Northwest are much healthier than others. These healthy populations usually occupy protected habitats such as the Hanford Reach...
No. Although sturgeon and catfish can be found in the same habitats and they both have barbels (whiskerlike growths extending from the jaw), they are not closely related. Sturgeon are much more primitive than catfish. There are some catfish sold for...