Myriapoda

Some bugs have many legs.

These bugs live on land. They like to stay in wet woods.

Centipedes are very fast. They hunt other small bugs at night. They can be very tiny. Some can be very large too.

Millipedes are slower. They eat old leaves on the ground. Most have many legs. One kind has over 1,000 legs!

These bugs have one pair of feelers on their heads. Some have eyes. Others have no eyes at all.

When they are young, they have only a few legs. They grow more legs as they get bigger. It is cool to see them grow!

Myriapods are a large group of land animals.

They include centipedes and millipedes. There are about 13,000 different species. Most live in moist forests. They help by breaking down old plants.

Centipedes are in a group called Chilopoda. They are fast hunters. They often hunt at night. Some centipedes are very small. Others can be quite large.

Millipedes are in a group called Diplopoda. They are slower than centipedes. Most eat dead leaves. They have many body segments. Most segments have two pairs of legs. One special kind has 1,306 legs!

Other small groups live in the soil. These are called symphylans and pauropods.

Most myriapods have one pair of antennae. These are feelers on their heads. Some have simple eyes. Others have no eyes at all. Myriapods breathe through tiny holes. These holes are called spiracles. They use these to get air.

When they are young, they are small. They have only a few legs. They grow more legs as they get older. They do this by shedding their skin.

Myriapods are a huge group of land-dwelling animals. They belong to a group of creatures called arthropods. This group includes famous animals like millipedes and centipedes. There are about 13,000 different species living on Earth today. Most of these animals live in moist forests. They play a very important role in nature. They help by breaking down old, decaying plant material.

These animals have many interesting body parts. Most myriapods have one pair of antennae on their heads. These are like feelers used to sense the world. Many have simple eyes, but some have none at all. House centipedes are different because they have large compound eyes.

They breathe through tiny holes called spiracles. These holes connect to a system that carries air through their bodies. They also have a long, tube-shaped heart that runs through them.

Scientists have studied these creatures for a long time. The study of myriapods is called myriapodology. People who do this work are myriapodologists. We know myriapods have been around for a very long time. The oldest fossil we know of is called Pneumodesmus. This fossil shows early evidence of breathing air on land. Other early fossils include Kampecaris obanensis and Archidesmus sp.

There are four main classes of living myriapods. Centipedes belong to the class Chilopoda. They are fast predators that hunt at night. Some are tiny, but the giant Scolopendra gigantea can be very large. Millipedes belong to the class Diplopoda. Most have many legs, but the species Eumillipes persephone has 1,306 legs!

Other groups include Pauropoda and Symphyla. Pauropods are very small and live in soil on almost every continent.

Growing up is a big job for a myriapod. Many young myriapods start with only a few segments and legs. They grow by a process called anamorphosis. This is a way of adding new segments and limbs as they grow. They do this by repeatedly shedding their old skin, which is called moulting. Some types add segments at every moult. Others stop adding segments once they become adults. This helps them reach their full size and shape.

Myriapods are a diverse group of land-dwelling arthropods. This subphylum includes well-known creatures like centipedes and millipedes. There are approximately 13,000 different species currently living on Earth. All myriapods are terrestrial, meaning they live on land. They play a vital role in many ecosystems. Most species live in moist forests where they act as detritivores. This means they eat decaying plant material and help recycle nutrients.

The anatomy of a myriapod is specialized for life on land. Most possess a single pair of antennae on their heads. They also have simple eyes, though some groups are entirely eyeless. For example, the centipede order Geophilomorpha lacks eyes completely. In contrast, house centipedes, or Scutigera, have large compound eyes.

Their mouthparts are located on the underside of the head. This includes an epistome and labrum for the upper lip. Inside the mouth, they use mandibles to process food. To breathe, they use spiracles, which are tiny openings. These connect to a tracheal system that moves air through the body.

Myriapods grow through a fascinating process called anamorphosis. Most young myriapods hatch with only a few body segments. They also start with very few pairs of legs. As they grow, they undergo repeated moulting, which is shedding their skin. During this process, they add new segments and limbs. There are three specific types of anamorphosis. Euanamorphosis involves adding segments during every moult, even after reaching maturity. Emianamorphosis adds segments only until a certain stage is reached. Finally, teloanamorphosis stops adding segments once the adult form is achieved.

Scientists categorize living myriapods into four distinct classes. The first is Chilopoda, which contains the centipedes. These are fast, nocturnal predators that hunt larvae, worms, and even small rodents. Some species, like Scolopendra gigantea, can grow quite large. The second class is Diplopoda, which includes the millipedes. Most millipedes are slower and feed on leaf litter. While most have between 36 and 400 legs, the species Eumillipes persephone has 1,306 legs.

The third class is Pauropoda, which are tiny soil-dwellers. They are often only 0.5 to 2.0 mm long.

The fourth class is Symphyla, known as garden centipedes. These are small animals that live in the soil.

History shows that myriapods have been part of Earth's biology for eras. Molecular evidence suggests they diversified during the Cambrian Period. However, the oldest known fossil record dates to the Late Silurian or Early Devonian. A fossil called Pneumodesmus provides early evidence of air-breathing on land. Other ancient species include Kampecaris obanensis and Archidesmus sp. We also know of extinct giants called Arthropleuridea. The most famous genus, Arthropleura, could reach lengths of up to 2.5 meters.

Classification of myriapods remains a subject of intense scientific debate. Researchers use different hypotheses to explain their evolutionary relationships. The Mandibulata hypothesis suggests they are related to Pancrustacea. The Atelocerata hypothesis links them closely to Hexapoda, or insects. Another theory, the Paradoxopoda hypothesis, suggests a link to Chelicerata. Some molecular studies even suggest Euthycarcinoids are their closest extinct relatives. Scientists use morphological studies of body shapes and molecular studies of DNA to test these ideas.

Understanding myriapods helps us grasp the complexity of terrestrial life. Their ability to move from water to land was a major evolutionary step. They occupy various niches, from microscopic soil dwellers to large predators. Some species even demonstrate bioluminescence, the ability to produce light. While some centipedes can bite and some millipedes produce noxious secretions, they are essential to the environment. By breaking down organic matter, they maintain the health of forest floors. The study of these animals, called myriapodology, continues to reveal new secrets about life on Earth.