Stingray Tail Barb (Tail Spine)
Dasyatis sp. cf. (likely Dasyatis or Aetobatus genus) • Body fossil; Chondrichthyes (Vertebrate)
Geological Period
Paleogene to Neogene (likely Eocene to Miocene)
Estimated Age
5 to 50 million years
Preservation Type
Permineralization; the original hydroxyapatite has been replaced or supplemented by minerals such as phosphate or calcium carbonate.
Condition Assessment
Good; the tip is intact and the distal portion is well-preserved, though the lateral serrations show moderate water-wear/abrasion.
Taxonomic Classification
Phylum: Chordata, Class: Chondrichthyes, Subclass: Elasmobranchii, Order: Myliobatiformes, Family: Dasyatidae (typical)
Morphological Description
Elongated, slender, tapering blade; serrated lateral margins (typically visible on edges, though worn here); central longitudinal ridge; hollow basal attachment point with a characteristic bilobed or trilobed cross-section for attachment to the tail musculature.
Rock Matrix
Matrix absent (isolated find); likely weathered from marine limestone, phosphate beds, or glauconitic sands.
Formation & Location
Commonly found in the Peace River Formation (Florida, USA), the Calvert Formation (Maryland/Virginia, USA), or the Eocene beds of Morocco.
Size & Dimensions
Approximately 3-4 inches in length; typical for medium to large stingray species.
Value & Rarity
Estimated Market Value
$15 - $40 USD
Auction Estimate
$20 - $50 USD (typically sold in lots with shark teeth)
Rarity Assessment
Uncommon to Common; while shark teeth are found in the thousands, complete barbs are more fragile and slightly less frequently recovered.
Scientific Significance
Provides data on the biodiversity of elasmobranchs in ancient marine or estuarine environments; indicates predator-prey dynamics and defensive evolution in rays.
Preparation Recommendations
Requires minimal preparation; clean with distilled water and a soft brush; consolidate with a reversible adhesive like Paraloid B-72 if micro-fractures appear.
Notable Features
The basal attachment point is exceptionally clear, showing the anatomical structure where it anchored to the ray's tail. The tan/brown coloration suggests a specific mineral environment, likely phosphate-heavy.