Leidfossiel

Leidfossiel is a German term that translates to "index fossil" or "guide fossil" in English. Index fossils are particularly useful in paleontology and geology for dating rock layers. These fossils are from species that lived for a relatively short geological period but were widespread geographically. Their presence in a rock stratum indicates that the rock was formed during the specific time period when that particular species existed. This allows geologists to correlate and date rocks from different locations, even if they are not physically connected. The effectiveness of a leidfossiel relies on its distinctiveness, wide distribution, and rapid evolution or extinction, meaning it only existed for a limited time. Common examples include certain ammonites and trilobites, which are found in numerous rock formations worldwide and represent specific geological ages. By identifying leidfossiel, scientists can establish a timeline for Earth's history and understand the sequence of rock layers.