270 Million B.C.T. - Olson's Extinction Occurred

Around 270 Million B.C.T., Olson's extinction occurred.

Olson's Extinction was a mass extinction that occurred 270 million years ago in the Early Guadalupian of the Permian period and which predated the Permian–Triassic extinction event. Everett Olson noted that there was a hiatus and a sudden change in between the Early Permian and Middle/Late Permian faunas. Since then this event has been realized across many groups, including plants, marine invertebrates, and tetrapods.

The first evidence of extinction came when Everett C. Olson noted a hiatus between Early Permian faunas dominated by pelycosaurs and therapsid dominated faunas of the Middle and Late Permian. First considered to be a preservational gap in the fossil record, the event was originally dubbed 'Olson's Gap'. To compound the difficulty in identifying the cause of the 'gap', researchers were having difficulty in resolving the uncertainty which exists regarding the duration of the overall extinction and about the timing and duration of various groups' extinctions within the greater process. Theories emerged which suggested the extinction was prolonged, spread out over several million years or that multiple extinction pulses preceded the Permian–Triassic extinction event. The impact of Olson's Extinction amplified the effects of the Permian–Triassic extinction event and the final extinction killed off only about 80% of species alive at that time while the other losses occurred during the first pulse or the interval between pulses.

During the 1990s and 2000s researchers gathered evidence on the biodiversity of plants, marine organism and tetrapods that indicated an extinction pulse preceding the Permian–Triassic extinction event had a profound impact on life on land. On land, even discounting the sparse fossil assemblages from the extinction period, the event can be confirmed by the stages of time bracketing the event since well preserved sections of the fossil record from both before and after the event have been found. The 'Gap' was finally closed in 2012 when it was confirmed that the terrestrial fossil record of the Middle Permian is well represented by fossil localities in the American southwest and European Russia and that the gap is not an artifact of a poor rock record since there is no correlation between geological and biological records of the Middle Permian.

There is no widely accepted theory for the cause of Olson's Extinction. Recent research has indicated that climate change may be a possible cause. Extreme environments were observed from the Permian of Kansas which resulted from a combination of hot climate and acidic waters particularly coincident with Olson’s Extinction . Whether this climate change was a result of Earth's natural processes or exacerbated by another event is unknown.

Fauna did not recover fully from Olson's Extinction before the impact of the Permian-Triassic extinction event. Estimates of recovery time vary, where some authors indicated recovery was prolonged, lasting 30 million years into the Triassic.

Several important events took place during Olson's Extinction, most notably the origin of therapsids, a group that includes the evolutionary ancestors of mammals.

A future extinction event, specifically due to anthropogenic changes, has been hypothesized by a number of scientific and environmental groups. Various possible causes include climate change, pollution, and habitat destruction. This is of great concern, due to the loss of biomes, the resources within them, and possible extinction of animal species. A better understanding of the process of extinction in the past may help determine the best course of action to preserve similar ecosystems today. Examining the conditions that led to the Olson's Extinction and the Permo-Triassic Extinction and the recovery of ecosystem from these events, may help contribute suitable solutions to resolving the current climate crisis.

Around 270 Million B.C.T., beetles evolved.

Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek koleos, meaning "sheath"; and pteron, meaning "wing", thus "sheathed wing". The reason for the name is that most beetles have two pairs of wings, the front pair, the "elytra", being hardened and thickened into a sheath-like, or shell-like, protection for the rear pair, and for the rear part of the beetle's body. The superficial consistency of most beetles' morphology, in particular their possession of elytra, has long suggested that the Coleoptera are monophyletic, but there is growing evidence that this is unjustified, there being arguments for example, in favor of allocating the current suborder Adephaga their own order, or very likely even more than one.

The oldest known insect that resembles species of Coleoptera date back to the Lower Permian (270 million years ago), although they instead have 13-segmented antennae, elytra with more fully developed venation and more irregular longitudinal ribbing, and an abdomen and ovipositor extending beyond the apex of the elytra. Today's true beetles have features that include 11-segmented antennae, regular longitudinal ribbing on the elytra, and genitalia that are internal.  At the end of the Permian, the biggest mass extinction in history took place, collectively called the Permian–Triassic extinction event: 30% of all insect species became extinct.  However, it is the only mass extinction of insects in Earth's history until today.