Q.Did aquatic life forms get fossilised? If, yes where do we come across such fossils?

Yes, aquatic life forms did get fossilized. The conditions in water bodies are often highly conducive to fossilization because dead organisms can quickly settle to the bottom and be covered by layers of sediment like sand, silt, or mud. This rapid burial protects them from scavengers and decomposition. Over geological timescales, these sediments compact and harden into sedimentary rocks, preserving the remains or impressions of the organisms within them. Therefore, we primarily come across such fossils in sedimentary rocks that were forme …

Fossils are the preserved remains or traces of organisms from a past geological age. They offer invaluable insights into the history of life on Earth, providing direct evidence of evolution and past environments. The process of fossilisation is a rare event, requiring a specific set of conditions to occur. Generally, for an organism to become a fossil, it must be buried quickly after death by sediment, protecting it from scavengers and decomposition. Over vast stretches of time, as more layers of sediment accumulate and exert pressure, the organic material is gradually replaced by minerals, turning the remains into rock.

Given these conditions, aquatic environments are often exceptionally conducive to fossilisation. When an aquatic organism dies, its body can sink to the bottom of a lake, river, or ocean. Here, it is frequently covered by layers of mud, sand, or silt that are constantly being deposited by water currents. This rapid burial is crucial because it isolates the remains from oxygen, which slows down decomposition, and from scavengers that might otherwise consume the body. The continuous accumulation of sediments in water bodies naturally creates the layers necessary for the formation of sedimentary rocks, which are the primary repositories of fossils.

Yes, aquatic life forms absolutely get fossilised. In fact, many of the most well-preserved and abundant fossils are of marine or freshwater organisms. The NCERT textbook, particularly in the context of evolution, discusses fossils and their significance. It highlights that fossils are typically found embedded in sedimentary rocks. For instance, the textbook mentions the discovery of a fossil fish in sedimentary rock, illustrating how such remains are preserved. This directly confirms that aquatic life forms do indeed become fossils. …

Reason from the fossilisation requirement (rapid burial in accumulating sediment) to the environment that satisfies it best — since sediment deposition is an ongoing, large-scale process mainly in water bodies, an …