Fossilized Rib Fragment
Mammalia indet. cf. marine mammal or ungulate rib fragment • Permineralized vertebrate body fossil
Geological Period
Neogene to Quaternary (Miocene to Pleistocene)
Estimated Age
2.5 to 10 million years old
Preservation Type
Mineral replacement and permineralization (frequently observed in river or beach-collected fossils where organic bone material is replaced by dense minerals)
Condition Assessment
Good. Solid and well-mineralized with a smooth, water-worn surface, though exhibiting breaks at both ends indicating it is an incomplete fragment.
Taxonomic Classification
Phylum: Chordata, Class: Mammalia, Order: Indeterminate (likely Marine Mammal or large Terrestrial Herbivore)
Morphological Description
Curved, elongated bone fragment with a dense cortical outer layer and visible structural curvature indicating it is likely a rib bone. The proximal or distal end shows partial articular features, while the shaft exhibits a smooth, glossy, jet-black surface resulting from mineral absorption.
Rock Matrix
Free of consolidated rock matrix; wet beach sand and silt adhering to the surface from recent recovery
Formation & Location
Coastal, river, or estuarine gravel beds known for Pleistocene fossil deposits (such as the Southeastern United States rivers or coastal beaches)
Size & Dimensions
Approximately 7 to 9 cm in length, fitting comfortably in an adult human palm
Value & Rarity
Estimated Market Value
$15 to $40 USD
Auction Estimate
$10 to $30 USD
Rarity Assessment
Common
Scientific Significance
Provides evidence of past mammalian fauna in the local depositional environment, though isolated unassociated rib fragments offer limited diagnostic taxonomic data beyond general paleoecological presence.
Preparation Recommendations
Wash gently with fresh water to remove any residual sand or salt, allow to dry completely, and store in a stable humidity environment. No chemical consolidants are strictly necessary if the bone is solidly mineralized.
Notable Features
Striking deep black coloration, high-gloss polished finish typical of water-tumbled beach or river finds, and clear anatomical curvature.