A terrestrial ecosystem is an ecosystem found only on land-forms. Six primary terrestrial ecosystems exist: tundra, taiga, temperate deciduous forest, tropical rain forest, grassland and desert.
About 2,000 species of firefly are found in temperate and tropical environments. Many are in marshes or in wet, wooded areas where their larvae have abundant sources of food. These larvae emit light and often are called "glowworms", in particular, in Eurasia. In the Americas, "glow worm" also refers to the related Phengodidae.
Snail is a common name that is applied most often to land snails, terrestrial gastropod mollusks. When the word "snail" is used in this most general sense, it includes not just land snails but also thousands of species of sea snails and freshwater snails.
Jellies are the major non-polyp form of individuals of the phylum Cnidaria. They are typified as free-swimming marine animals consisting of a gelatinous umbrella-shaped bell and trailing tentacles. The bell can pulsate for locomotion, while stinging tentacles can be used to capture prey.
A geomagnetic reversal is a change in the Earth’s magnetic field such that the positions of magnetic north and magnetic south are interchanged. The Earth’s field has alternated between periods of normal polarity, in which the direction of the field was the same as the present direction, and reverse polarity, in which the field was the opposite.
Sharks are a group of fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head.
Corals are marine invertebrates in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.
The law of conservation of energy states that the total energy of an isolated system cannot change—it is said to be conserved over time. Energy cannot be created or destroyed, but can change form; for instance, chemical energy can be converted to kinetic energy.