Fossil Sand Dollar
cf. Encope sp. • Body fossil, invertebrate echinoid
Geological Period
Neogene (Miocene to Pliocene epochs)
Estimated Age
5 to 23 million years old
Preservation Type
Calcitic replacement and permineralization within a soft sedimentary matrix
Condition Assessment
Good, showing minor edge wear and surface chipping but preserving the delicate petaloid markings and structural lunules clearly
Taxonomic Classification
Phylum Echinodermata, Class Echinoidea, Order Clypeasteroida, Family Mellitidae, Genus Encope (or similar fossil clypeasteroid)
Morphological Description
Flattened, disk-shaped test exhibiting a prominent five-petaloid ambulacral design on the aboral surface, characteristic pores, and distinct peripheral notches along the margin with at least one notable lunule or elongated opening towards the posterior.
Rock Matrix
Light-colored calcareous siltstone or fine-grained sandy limestone
Formation & Location
Peace River Formation or Tamiami Formation, Florida, USA
Size & Dimensions
Approximately 6 to 8 centimeters in diameter, standard adult size for this taxonomic group
Value & Rarity
Estimated Market Value
$15 - $40 USD
Auction Estimate
$20 - $50 USD
Rarity Assessment
Common, frequently found in fossil-rich marine deposits of the southeastern United States
Scientific Significance
Provides insights into shallow marine paleoenvironments, benthic ecology, and the evolutionary adaptations of irregular echinoids to high-energy sandy substrate habitats
Preparation Recommendations
Gentle mechanical cleaning using soft brushes or pneumatic air abrasion to remove residual matrix; store in a dry, stable environment away from high humidity
Notable Features
Well-defined central flower-like petaloids and clear marginal indentations with a distinct posterior lunule opening