56MM Pygurus Marmonti Sea Urchin Fossil Sand Dollar Jurassic Age Madagascar

Location: Majanga, Madagascar

Weight: 3.2 Ounces

Dimensions: 56MM

The item pictured is the one you will receive.

Pygurus marmonti, the sand dollar, is an extinct Jurassic echinoid known from fossil deposits dating between approximately 145 and 200 million years ago. As a member of the echinoid lineage, it exhibited pentaradial symmetry expressed through a characteristic five-pointed pattern on the test. Specimens from Madagascar are particularly notable for their preservation quality, providing valuable data for studies of Jurassic marine ecosystems.

The species inhabited shallow marine substrates where it likely engaged in burrowing behavior. Following death, rapid sediment burial protected the test from degradation, allowing fossilization through mineral replacement and compaction. This process preserved fine morphological features, including structural symmetry and surface ornamentation.

Research on Pygurus marmonti contributes to understanding echinoid evolution and Jurassic paleoecology while also demonstrating how favorable sedimentary conditions can preserve delicate marine organisms in exceptional detail.

Please be aware of the nature of fossils:

Being buried under the ground for millions of years under tons of pressure tends to be rough. No fossil comes out of the ground whole and perfect. Most fossils have undergone some restoration, while others are altered by man simply to enhance their presentation in different ways. The workers in Madagascar do a very professional job of unearthing and preserving these natural treasures; however, natural cracks are visible on the surface. These are part of the natural beauty of the fossil and are not considered defects.