Kehafossiilide

Kehafossiilide (body fossils) are preserved remains of organisms or their body parts, such as bones, teeth, shells, scales, or impressions of soft tissues. They are distinguished from trace fossils, which record activities such as footprints, burrows, or feeding marks.

The formation of kehafossiilide typically requires rapid burial in sediment or other preservation media to protect remains from decay and scavenging. Common pathways include permineralization and petrification, where minerals replace or fill porous tissues; molds and casts, where an impression of the organism is preserved; carbonization, where a thin film of carbon outlines the specimen; and preservation in resin, ice, or tar. Various environments, from river deltas to deep-sea sediments, contribute to different preservation styles and time ranges.

Kehafossiilide provide direct evidence of anatomy, size, and morphology, enabling paleontologists to infer phylogeny, development, and ecological roles. They underpin biostratigraphy and dating within sedimentary sequences, with some fossils acting as index fossils. Absolute ages are often refined through radiometric dating of surrounding rocks or associated volcanic layers.

Preservation is inherently biased. Hard parts such as bones and shells are more likely to fossilize than soft tissues, and exceptional conditions are required for soft-tissue preservation. The fossil record is therefore incomplete and uneven across time and geography, influencing our understanding of past life. Examples of known kehafossiilide include dinosaur bones, mammoth tusks, trilobites, ammonites, corals, and plant impressions.