Dinosaur brains from baby to adult

New research by a University of Bristol palaeontology post-graduate student has revealed fresh insights into how the braincase of the dinosaur Psittacosaurus developed and how this tells us about its posture.

Oldest axial fossils discovered for the genus Australopithecus

Scientists have published an article describing the oldest axial fossils yet discovered for the genus Australopithecus. Dated 4.2 million years ago, these and other fossils recovered from the Assa Issie site in the Middle ...

Human ancestors were 'grounded,' new analysis shows

African apes adapted to living on the ground, a finding that indicates human evolved from an ancestor not limited to tree or other elevated habitats. The analysis adds a new chapter to evolution, shedding additional light ...

Human-like walking mechanics evolved before the genus Homo

Ever since scientists realized that humans evolved from a succession of primate ancestors, the public imagination has been focused on the inflection point when those ancestors switched from ape-like shuffling to walking upright ...

Human skull evolved along with two-legged walking, study confirms

The evolution of bipedalism in fossil humans can be detected using a key feature of the skull—a claim that was previously contested but now has been further validated by researchers at Stony Brook University and The University ...

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Bipedalism

Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs, or legs. An animal or machine that usually moves in a bipedal manner is known as a biped ( /ˈbaɪpɛd/), meaning "two feet" (from the Latin bi for "two" and ped for "foot"). Types of bipedal movement include walking, running, or hopping, on two appendages (typically legs).

Relatively few modern species are habitual bipeds whose normal method of locomotion is two-legged. Within mammals, habitual bipedalism has evolved six times, with the macropods, kangaroo mice, dipodids, springhare , pangolins and homininan apes. In the Triassic period some groups of archosaurs (a group that includes the ancestors of crocodiles) developed bipedalism; among their descendants the dinosaurs all the early forms and many later groups were habitual or exclusive bipeds; the birds descended from one group of exclusively bipedal dinosaurs.

A larger number of modern species are capable of bipedal movement for a short time in exceptional circumstances. Several non-archosaurian lizard species move bipedally when running, usually to escape from threats. Many animals rear up on their hind legs whilst fighting or copulating. A few animals commonly stand on their hind legs, in order to reach food, to keep watch, to threaten a competitor or predator, or to pose in courtship, but do not move bipedally.

There are two main types of bipedal locomotion: macropods, some smaller birds[citation needed], and heteromyid rodents move by hopping on both legs simultaneously; other groups, including apes and larger birds, walk or run by moving one leg at a time.

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