Opposition (anatomy)
As opposition or opposability is referred to in the anatomy , the ability of the thumb , the other fingers faced to be, or in some animals the ability to first toe the other to face.
In humans, the thumb is twisted by 130 ° compared to the other fingers, which is what makes the tweezers grip between the thumb and index finger possible.
In addition to humans, the following animals are also capable of opposing the thumb or the big toe:
- Giant pandas and small pandas have five claws and an overlong carpal bone that acts as a thumb.
- Koalas have two thumbs and three opposite fingers on their feet and hands.
- Opossum rats have opposable thumbs.
- In many primate species , the thumb can also be opposed.
- An opposable big toe is a feature of all primates with the exception of humans .
- In many bird species the first toe points backwards and can be opposed to the three front toes (see also bird's foot ).
- Chameleons , with these the feet are shaped into pincers, whereby two and three toes are fused together.
- Crustaceans and scorpions have powerful claws on their front extremities.
- Fire ants have two opposable bristles on their front legs.
- Dromaeosauridae Group within the theropods , lizard-basin dinosaurs , to which the Velociraptor , which became popular through the Jurassic Park film , is counted.
Koalas
Parrot holds a nut with its foot
Mountain chameleon
