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The Quaternary prehistory Portal

Introduction

The Quaternary (/kwəˈtɜːrnəri, ˈkwɒtərnɛri/ kwə-TUR-nə-ree, KWOT-ər-nerr-ee) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ago to the present. As of 2023, the Quaternary Period is divided into two epochs: the Pleistocene (2.58 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today); a third epoch, the Anthropocene, has recently been proposed, but it is not officially recognised by the ICS.

The Quaternary Period is typically defined by the cyclic growth and decay of continental ice sheets related to the Milankovitch cycles and the associated climate and environmental changes that they caused. (Full article...)

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Archaeoindris fontoynontii is an extinct, giant lemur and the largest primate known to have evolved on Madagascar, comparable in size to a male gorilla. It belonged to a family of extinct lemurs known as "sloth lemurs" (Palaeopropithecidae), and because of its extremely large size, it has been compared to the ground sloths that once roamed North and South America. It was most closely related to Palaeopropithecus, the second largest type of sloth lemur. Along with the other sloth lemurs, Archaeoindris was related to the living indri, sifakas, and woolly lemurs, as well as the recently extinct monkey lemurs (Archaeolemuridae). The genus, Archaeoindris, translates to "ancient indri-like lemur", even though it probably became extinct recently, around 350 BCE.

The most reliable size estimate of Archaeoindris suggests a body mass of 160 kg (350 lb). Misattributions and limited remains have resulted in varying opinions about the way Archaeoindris moved in its environment, ranging from tree-dwelling to ground-dwelling. Its skeleton suggests it was a deliberate climber that visited the ground to travel. The diet of Archaeoindris was mostly leaves, and its habitat—prior to human arrival—was a mix of woodlands, bushlands, and savanna, rich in lemur diversity. Although it was a rare lemur, it was still extant when humans first arrived on Madagascar, and it would have been vulnerable to hunting and habitat loss. (see more...)

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On the Origin of Species, published in 1859, is a work of scientific literature by Charles Darwin which is considered to be the foundation of evolutionary biology. Darwin's book introduced the scientific theory that populations evolve over the course of generations through a process of natural selection. It presented a body of evidence that the diversity of life arose by common descent through a branching pattern of evolution. Darwin included evidence that he had gathered on the Beagle expedition in the 1830s and his subsequent research findings. Ideas about the transmutation of species were controversial as they conflicted with beliefs that species were unchanging parts of a designed hierarchy and that humans were unique and unlike animals.

The book was written for non-specialist readers and attracted widespread interest upon its publication. As Darwin was an eminent scientist, his findings were taken seriously and the evidence he presented generated scientific, philosophical, and religious discussion. Within two decades there was widespread scientific agreement that evolution, with a branching pattern of common descent, had occurred, but scientists were slow to give natural selection the significance that Darwin thought appropriate. During the "eclipse of Darwinism" from the 1880s to the 1930s, various other mechanisms of evolution were given more credit. With the development of the modern evolutionary synthesis in the 1930s and 1940s, Darwin's concept of evolutionary adaptation through natural selection became central to modern evolutionary theory, and it has now become the unifying concept of the life sciences. (see more...)

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A dire wolf skeletal mount on display at the National Museum of Nature and Science, Tokyo, Japan.
Photo credit: Momotarou2012

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Did you know?

... that Professor Clive Finlayson has theorized that the genetic similarities between Neanderthals and humans are not only due to interbreeding but could also originate from a common African ancestor?
... that the fossil relative of the House Sparrow Passer predomesticus is known only from two upper jaw bones?
...that the barnacle Megabalanus can reach 7 cm in length?
... that Francisco Javier Muñiz was considered the first important naturalist from Argentina?
... that the discovery of Babakotia radofilai, an extinct species of sloth lemur, helped to resolve the relationship between the indriids, sloth lemurs, and monkey lemurs?