Fossilized Mammal Rib Fragment
Mammalia indet. (cf. medium-sized terrestrial mammal rib) • Vertebrate body fossil, permineralized bone fragment
Geological Period
Neogene to Quaternary (Miocene to Pleistocene epochs)
Estimated Age
0.01 to 5 million years ago
Preservation Type
Mineral replacement and permineralization with heavy incorporation of iron or manganese oxides, resulting in a dark, lustrous black coloration.
Condition Assessment
Fair to Good. The specimen is an incomplete fragment lacking both articulating ends, but the preserved mid-section exhibits excellent fossilization with a stable, dense structure and minimal surface weathering.
Taxonomic Classification
Phylum: Chordata, Class: Mammalia, Order: Indeterminate, Family: Indeterminate
Morphological Description
Curved, elongated fragment of a flat bone exhibiting a distinct T-shaped or grooved cross-section characteristic of mammalian ribs. Smooth, highly polished exterior surface with broken, jagged proximal and distal ends revealing internal dense cortical bone structure.
Rock Matrix
No adhering consolidated rock matrix; found loose in a sandy/muddy beach or riverine environment, potentially sourced from nearby coastal or estuarine fossiliferous deposits.
Formation & Location
Coastal Pleistocene terrace deposits, river gravels, or offshore fossil beds (commonly found in regions such as the Southeastern United States coastline or similar fossil-rich shores).
Size & Dimensions
Approximately 7-8 cm in length, fitting comfortably in the palm of an adult human hand.
Value & Rarity
Estimated Market Value
15 to 45 USD
Auction Estimate
20 to 50 USD
Rarity Assessment
Common. Fragmentary fossilized mammal bones are frequently recovered by beachcombers and fossil hunters in coastal and riverine deposits worldwide.
Scientific Significance
Provides evidence of past terrestrial mammalian fauna in the local region during the Late Cenozoic, contributing to paleoenvironmental reconstructions of coastal plains and river valleys.
Preparation Recommendations
Wash gently with fresh water to remove residual salt or sand, allow to air dry completely, and optionally treat with a dilute solution of polyvinyl butyral (PVB) or Paraloid B-72 for long-term stabilization if kept in fluctuating humidity conditions.
Notable Features
Striking jet-black coloration due to mineral staining from aquatic or sediment burial, and a well-defined cross-sectional anatomy clearly indicating its origin as a mammalian rib bone.