Ecdysozoa facts for kids
Quick facts for kids EcdysozoaTemporal range: Lower Cambrian – Recent
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Ecdysozoa
Aguinaldo et al., 1997
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Ecdysozoa are a big group of animals. They are special because they all shed their outer skin or shell as they grow. Think of it like a snake shedding its skin, or a crab getting rid of its old shell! This process is called ecdysis or moulting. This group includes many animals you know, like insects, spiders, crabs, and worms.
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What Are Ecdysozoa?
Ecdysozoa is a very large group of animals. It includes many different types of creatures. These animals are all part of a bigger group called protostomes. A protostome is a kind of animal that develops its mouth first as an embryo.
This group is considered a "superphylum." A phylum is a major group in how scientists classify living things. So, a superphylum is an even larger grouping of related phyla.
Animals in This Group
The Ecdysozoa superphylum contains some very well-known animal groups. The most famous are the Arthropoda. This phylum includes:
- Insects (like butterflies and beetles)
- Crustaceans (like crabs and lobsters)
- Arachnids (like spiders and scorpions)
- Myriapods (like centipedes and millipedes)
Another important group in Ecdysozoa is the Nematoda. These are also known as roundworms. There are many other smaller phyla too.
How Scientists Found This Group
Scientists first described the Ecdysozoa group in 1997. They used new ways to study how animals are related. They looked at the DNA of different animals. Specifically, they studied a part of their RNA called 18S ribosomal RNA genes.
By comparing these genes, scientists could build "phylogenetic trees." These trees show how different species are connected through evolution. The studies showed that all these animals were closely related.
Later, in 2008, a big study strongly supported the idea of Ecdysozoa. It confirmed that they form a clade. A clade means a group of organisms that all came from a single common ancestor. It includes that ancestor and all its descendants.
Why Shedding Skin is Important
The main reason these animals are grouped together is because of a special feature. They all shed their outer covering. This outer covering is called an exoskeleton. It's like an external skeleton that protects their bodies.
As these animals grow, their exoskeleton doesn't grow with them. So, they have to shed it and grow a new, larger one. This process is called ecdysis. It's a very important part of their life cycle.
This shedding process is a key "morphological character." This means it's a physical feature that helps scientists classify them. It shows they share a common ancestor who also shed its skin.
See also
In Spanish: Ecdysozoa para niños
