Arthropoda

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Arthropoda
Kingdom:	Animalia
Phylum:	Arthropoda
Class:
Order:
Family:	'

Arthropoda is a phylum of invertebrate animals having an exoskeleton, a segmented body, and jointed appendages. Arthropods form the largest phylum in the animal kingdom, with over a million described species.

Characteristics

Arthropods are characterized by their chitinous exoskeleton, which provides both protection and support. This exoskeleton is periodically shed through a process called molting or ecdysis.

The body of an arthropod is divided into segments, each of which may bear a pair of appendages. These appendages are often specialized for various functions, such as locomotion, feeding, and sensory perception.

Classification

Arthropoda is divided into several subphyla, each containing a diverse array of species:

• Chelicerata - Includes spiders, scorpions, and horseshoe crabs.
• Myriapoda - Includes centipedes and millipedes.
• Crustacea - Includes crabs, lobsters, and shrimp.
• Hexapoda - Primarily includes insects, the most diverse group of arthropods.

Evolution

Arthropods are believed to have evolved from a common ancestor with annelids, as both groups share a segmented body plan. The earliest arthropods appeared in the Cambrian period, over 500 million years ago.

Importance

Arthropods play crucial roles in ecosystems as pollinators, decomposers, and prey for other animals. They are also of significant economic importance, with many species being used in agriculture and biotechnology.

See also

• Invertebrate
• Exoskeleton
• Biodiversity

External links

• Arthropoda on WikiMD