Guadalupian

The Guadalupian is the second and middle series/epoch of the Permian. It came after the Cisuralian and before the Lopingian. The name Guadalupian comes from the Guadalupe Mountains in New Mexico and Texas. This time period lasted from about 274.4 million to 259.51 million years ago.

During the Guadalupian, many important changes happened in the world of animals. Therapsids, which were early ancestors of mammals, began to rise in number and variety. There was also a smaller event called Olson's Extinction, where some species died out. Later in this period, a much bigger mass extinction took place, known as the end-Capitanian extinction event. This middle part of the Permian period played a big role in shaping life on Earth.

Name and background

The Guadalupian is the middle part of the Permian period. It used to be called the Middle Permian, but scientists changed the name to help match rock layers all around the world. The name "Guadalupian" comes from the Guadalupe Mountains in Texas and New Mexico. Before the Guadalupian was the Cisuralian, and after it came the Lopingian.

Biodiversity

Therapsids became the main land animals during the Guadalupian, taking the place of pelycosaurs. Therapsids came from a group called sphenacodonts and had four main groups: dinocephalians, anomodonts, biarmosuchians, and theriodonts. After a time of growing diversity, the dinocephalians disappeared later in the Guadalupian.

A mass extinction happened around 273 million years ago early in the Guadalupian, before the bigger Permian–Triassic extinction event. This was first called Olson's Gap because it seemed like fossils were hard to find. Since the 1990s, it has been known as Olson's Extinction. During this time, about two-thirds of land vertebrates disappeared worldwide. Life became less diverse for a while, then increased again before dropping once more at the end of the Guadalupian. We don’t fully understand what caused Olson's Extinction, but climate change might have played a role.

Climate

The climate during the Guadalupian was similar to parts of central Asia today. Pangea, a huge supercontinent, had very hot, dry summers and cold, bitter winters. Near the equator, there was a desert that could reach temperatures of 74 degrees Celsius. The coastal areas were tropical and experienced heavy rains called monsoons.

For most of this time, the climate was warm and tropical but began to become drier. This change stopped the formation of coal and created new homes for various animals and plants. Later, temperatures dropped, many coral reefs disappeared, and increased volcanic activity led to difficult conditions for life.

Subdivisions

The Guadalupian period is divided into three stages: the Roadian, Wordian, and Capitanian.

The Roadian Stage lasted from about 272.3 million to 268.8 million years ago. During this time, a major event called Olson's Extinction happened, which affected many land animals. This event led to the rise of therapsids, the ancestors of mammals. The Wordian Stage followed, from about 268.8 million to 265.1 million years ago. The Capitanian Stage was the last stage, from about 265.1 million to 259.8 million years ago. It ended with environmental changes and mass extinctions, affecting many sea creatures and some land animals.

Other subdivisions

Some people use different names to describe parts of the Guadalupian. In Europe, this time is sometimes called the Kazanian or Maokovian, lasting from about 270.6 million to 260.4 million years ago. In New Zealand, it may be referred to as the Braxtonian, covering the same time period.