The fossil type described in your definition is known as "preserved fossils" or "microfossils." These fossils preserve the original structure of the organism in materials such as amber, tar, peat, or ice, allowing for detailed study of the organism's features and sometimes even soft tissues.
If you're looking for a more specific term depending on the preservation medium, you could refer to:
- Amber fossils: when organisms are trapped in tree resin that hardens.
- Tarseeps: fossils preserved in natural asphalt (tar).
- Peat bog fossils: organisms preserved in wet, acidic environments.
- Frozen fossils: when organisms are preserved in ice.
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