Fossilized Crab Claw Finger (Dactyl)
cf. Menippe mercenaria (Florida Stone Crab) • Invertebrate Body Fossil (Skeletal part)
Geological Period
Neogene to Quaternary (likely Miocene, Pliocene, or Pleistocene)
Estimated Age
Approximately 2.5 to 15 million years
Preservation Type
Replacement and permineralization with phosphate and iron minerals, resulting in the characteristic black coloration common in Florida marine deposits.
Condition Assessment
Good to Very Good; the tip is intact and the surface exhibits high lustre, though the proximal articulation shows minor beach-wear/pitting.
Taxonomic Classification
Phylum: Arthropoda, Class: Malacostraca, Order: Decapoda, Family: Xanthidae or Menippidae
Morphological Description
A curved, conical, and robust dactyl (movable finger) of a crab cheliped. It features a smooth, dark, highly mineralized surface with a sharp distal tip and a thickened proximal articulation base where it would attach to the manus.
Rock Matrix
None; the specimen is an isolated find likely recovered from beach sands or nearshore phosphate-rich deposits.
Formation & Location
Venice Beach, Florida; likely originating from the Peace River Formation or Tamiami Formation.
Size & Dimensions
Approximately 1 to 1.5 inches in length. This is a typical size for an adult Stone Crab dactyl.
Value & Rarity
Estimated Market Value
$5.00 - $15.00 USD
Auction Estimate
$10.00 - $20.00 USD (typically sold in bulk lots or as small educational specimens)
Rarity Assessment
Common; these are frequently found by beachcombers in the Sarasota/Venice area of Florida, known as the 'Shark Tooth Capital of the World'.
Scientific Significance
Provides data on the historical distribution of decapod crustaceans in the Gulf Coast region and indicates the high-energy, mineral-rich paleoenvironment of the Florida shelf.
Preparation Recommendations
Requires minimal intervention. Rinse with fresh water to remove salts; can be coated with a thin layer of Paraloid B-72 for extra shine and stabilization.
Notable Features
The deep black 'patina' is a signature of fossils from Venice Beach, caused by the heavy concentration of phosphate in the local geological strata.
Notes
Sarasota Fl Vince beach