forelimb
Quick Summary
The term "forelimb" refers to the limb situated anteriorly in a vertebrate, such as an arm, wing, fin, or leg. In humans and other primates, the arm is considered a forelimb, extending from the shoulder to the elbow and then to the forearm and hand. The human arm consists of the humerus in the upper arm, the radius and ulna in the forearm, and the carpal, metacarpal, and phalangeal bones in the hand. Muscles like the triceps, brachialis, and biceps are crucial for arm movement.12
Primates inherited a basic quadrupedal limb structure, but many have adapted their forelimbs for arboreal locomotion, like swinging through trees. Humans, however, have evolved an upright, bipedal posture, freeing the upper limbs for prehensile use. This adaptation has led to significant changes in the musculature and bone structure of the human upper limb, enhancing manipulative abilities, particularly in the thumb.34
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dinosaurProsauropodaBecause their forelimbs are conspicuously shorter than their hind limbs, they have often been reconstructed poised on their hind legs in a bipedal stance. Their anatomy, however, clearly indicates that some of them could assume a quadrupedal (four-footed) position. Footprints generally attributed to prosauropods appear to substantiate…
Read MoreBecause their forelimbs are conspicuously shorter than their hind limbs, they have often been reconstructed poised on their hind legs in a bipedal stance. Their anatomy, however, clearly indicates that some of them could assume a quadrupedal (four-footed) position. Footprints generally attributed to prosauropods appear to substantiate…
Read More- dinosaurTheropoda
The forelimbs varied widely from the slender, elongated ones of Struthiomimus, for example, to shorter, more massively constructed grasping appendages like those of Allosaurus, to the greatly abbreviated arms and hands of Tyrannosaurus, to the abbreviated, stout limb and single finger of Mononykus, to the range…
Read MoreThe forelimbs varied widely from the slender, elongated ones of Struthiomimus, for example, to shorter, more massively constructed grasping appendages like those of Allosaurus, to the greatly abbreviated arms and hands of Tyrannosaurus, to the abbreviated, stout limb and single finger of Mononykus, to the range…
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primateFour types of locomotion… is performed exclusively with the forelimbs. Quadrupedalism involves both forelimbs and hind limbs, of course, although not to an equal extent. Some quadrupeds are hind limb-dominated; in others, the forelimb and the hind limb are equally important. The hind limb-dominated primates, such as the langurs and colobus monkeys, employ a…
Read More… is performed exclusively with the forelimbs. Quadrupedalism involves both forelimbs and hind limbs, of course, although not to an equal extent. Some quadrupeds are hind limb-dominated; in others, the forelimb and the hind limb are equally important. The hind limb-dominated primates, such as the langurs and colobus monkeys, employ a…
Read More- primateSize in evolutionary perspective
Such adaptations of the forelimbs would have had the effect of equalizing the role of the limbs. The limbs of vertical clingers are functionally disparate, the lower pair being dominantly propulsive and the upper secondary and purely supportive. The limbs of quadrupeds, however, are more homogeneous, both pairs having…
Read MoreSuch adaptations of the forelimbs would have had the effect of equalizing the role of the limbs. The limbs of vertical clingers are functionally disparate, the lower pair being dominantly propulsive and the upper secondary and purely supportive. The limbs of quadrupeds, however, are more homogeneous, both pairs having…
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