Fossilized Steinkern Gastropods from the Cretaceous Period
Fossil Gastropod Steinkern, Silicified in Quartz from the Cretaceous period, found in Madhya Pradesh, India.
What is a Steinkern?
A Steinkern is a fascinating type of fossil that represents the internal cast of a once-hollow organic structure, such as a mollusc shell. Over millions of years, as the original shell or structure disintegrates or dissolves, sediment or mud fills the void and eventually hardens into stone. The result is a detailed fossilized outline that retains the shape of the original organism, offering a glimpse into the past.
This weeks featured fossil is a Steinkern gastropod belonging to the genus Lymnaea, a group of air-breathing freshwater snails that lived millions of years ago during the Cretaceous period. The genus Lymnaea is particularly known for its small to large-sized aquatic gastropod mollusks, which inhabited freshwater environments.
Silicified Quartz with Chalcedony
One of the most striking features of this fossil is its silicified quartz composition, which has replaced the original organic material over time. The process of silicification has preserved the intricate details of the gastropod, turning it into a durable and visually stunning fossil. The quartz has undergone further mineral transformation, becoming chalcedony, a type of microcrystalline quartz known for its waxy lustre and translucency.
The specimens exhibit a beautiful marble-like effect, with areas of opacity on the underside, making it not only a piece of natural history but also a work of art. The warm, earthy tones of brown enhance its visual appeal, adding a touch of elegance to any collection.
Historical Significance and Provenance
Dating back to the Maastrichtian stage of the Cretaceous period, this fossil is estimated to be around 70 to 66 million years old. It was discovered in Betul, a region in Madhya Pradesh, a state located in central India. The area's rich geological history has made it a significant site for fossil discoveries, with this gastropod being one of the rarer finds.