Pros: 1  Works equally well in open terrain, under cover or in a gym. 2  Accurate on flat or hilly terrain and when making quick, sharp turns (e.g., when trail running or on an indoor track). 3  Lightweight design is sleeker than most GPS-enabled SDMs.
Definitions for mass extinction. Here are all the possible meanings and translations of the word mass extinction. Wiktionary(0.00 / 0 votes)Rate this definition: mass extinction(Noun) A sharp decrease in the total number of species in a relatively short period of time.
By contrast, mass extinctions appear as abrupt discontinuities in the fossil record, affect many species at once, and have a much greater impact on biodiversity. Most scientists agree that five extinction events stand out from the rest. Each time, at least 50 to 90 percent of all species living on Earth disappeared.