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.
Mass extinctions are periodic rises in the extinction rate above the background level. They are events which are not caused by changes in habitat or competition but catastrophes. Perhaps over 95% of all extinctions have occurred as background events, with the rest consisting of catastrophic events which:-.