Acritarchs are microscopic fossils of any kind. They can be archaea, bacteria, or eukaryotes. They can be algae or even egg cases of small metazoa. The biggest acritarchs are about one millimeter in diameter. Acritarchs are a general name for these types of fossils when they cannot be more accurately classified. Once a more accurate classification is made, the organism is removed from the acritarch class.
The first acritarchs are found in the later Paleoprotozoic era. They are simple organisms, and are not very abundant. In the Mesoprotozoic era, acritarchs are more abundant and appear to be definite eukaryotes. They have ellipical shapes, processes, and appear in multicellular colonies.
Acritarchs from the Neoprotozoic era have a great variety of shapes and processes. Some look like modern fungi and algae. Many also had tiny spines. Some people think that the spines were for protection against early predators or grazers who fed on the acritarchs. Here are some pictures of acritarchs.
The first acritarchs are found in the later Paleoprotozoic era. They are simple organisms, and are not very abundant. In the Mesoprotozoic era, acritarchs are more abundant and appear to be definite eukaryotes. They have ellipical shapes, processes, and appear in multicellular colonies.
Acritarchs from the Neoprotozoic era have a great variety of shapes and processes. Some look like modern fungi and algae. Many also had tiny spines. Some people think that the spines were for protection against early predators or grazers who fed on the acritarchs. Here are some pictures of acritarchs.
No comments:
Post a Comment