Fossil Sand Dollar Fragment
Clypeasteroidea indet. (cf. Mellita or Scutella) • Invertebrate body fossil, echinoid
Geological Period
Neogene (Miocene to Pliocene)
Estimated Age
5 to 23 million years
Preservation Type
Calcitic permineralization and replacement within a soft carbonate matrix
Condition Assessment
Poor, highly incomplete fragment with a major fresh or weathered fracture bisecting the test, missing approximately 50 percent or more of the original specimen
Taxonomic Classification
Phylum Echinodermata, Class Echinoidea, Order Clypeasteroida, Family Scutellidae
Morphological Description
Fragmentary fossilized echinoid test displaying a portion of the characteristic petaloid ambulacral zones on the upper surface. Porous internal microstructure visible along the broken fracture edge. Surface shows chalky white coloration with subtle textural relief along the ambulacral grooves.
Rock Matrix
White chalky limestone or calcareous marl matrix adhering to the fossil structure
Formation & Location
Commonly found in coastal marine formations such as the Hawthorn Group (Southeastern USA) or similar shallow-marine Neogene deposits globally
Size & Dimensions
Approximately 5 cm across the longest remaining axis, representing a medium-sized adult sand dollar approximately 7 to 8 cm in complete diameter
Value & Rarity
Estimated Market Value
5 to 15 USD
Auction Estimate
Not suitable for auction; typical educational or bulk study specimen
Rarity Assessment
Common
Scientific Significance
Provides local paleoenvironmental indicators of shallow, high-energy or moderate-energy sandy marine shelf environments during the Neogene period
Preparation Recommendations
Gentle mechanical cleaning with a soft brush to remove loose chalky matrix; store in a dry environment to prevent crumbling of the fragile porous matrix
Notable Features
Exposed internal trabecular micro-architecture along the major break, offering a clear cross-sectional view of the echinoid plate structure
Notes
This is a sand dollar