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Arcellinida

Adapted from Wikipedia · Adventurer experience

Microscopic shell of Netzelia corona, a single-celled organism called a testate amoeba.

Arcellinid testate amoebae, also known as Arcellinida, Arcellacean, or lobose testate amoebae, are tiny, single-celled creatures called protists. They are special because they live inside a simple shell called a test. You can find these organisms in many places, such as soils, leaf litter, peat bogs, and near or in fresh water.

Arcellinid testate amoebae move and capture food using their pseudopodia, which are temporary parts that come out of their cells. Most scientists think they reproduce asexually by splitting into two parts. This process is called binary fission. New research suggests these creatures might recombine genetically more often than we thought, especially for amoeboid protists like them.

Morphology

Arcellinida always have a shell, called a test, outside their cell. These shells are made from organic or mineral materials. The test has one main opening.

These shells can help scientists learn about past environments. By studying old shells, researchers can learn about past climate change and water conditions during the Holocene. Different species of testate amoebae live in specific environments, which helps scientists understand past conditions.

Evolutionary history

Fossils of these tiny creatures go back to the Tonian stage of the Proterozoic, about 789 to 759 million years ago. By 730 million years ago, they had developed into many different types.

Scientists think these creatures might have come from more than one ancient ancestor. Their old shells are often found in fossilized amber, and some have been found in very old lake sediments. They have changed very little over millions of years.

Classification

The Arcellinida are tiny, single-celled organisms. They live in soil, leaf litter, peat bogs, and near fresh water. They have a simple shell called a "test". They use temporary body parts called pseudopodia to move and eat.

The Arcellinida are grouped into several suborders and families, including:

Related articles

Asexual reproduction
Holocene
Tonian
Proterozoic

This article is a child-friendly adaptation of the Wikipedia article on Arcellinida, available under CC BY-SA 4.0.

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