Hagfish or Clam Boring Trace Fossil (Hagfish Burrow / Entobia-type trace)
cf. Entobia isp. or bioerosional trace fossil incertae sedis • Trace fossil (ichnofossil), invertebrate or primitive fish dwelling structure / bioerosion trace
Geological Period
Neogene to Quaternary (Miocene to Recent)
Estimated Age
0.01 to 5 million years (likely Pleistocene to Holocene given typical beach find preservation)
Preservation Type
Bioerosion in sedimentary rock, sub-fossilization with physical abrasion and rounding via wave action
Condition Assessment
Good (water-worn beach specimen, complete trace structure with smoothing from wave action)
Taxonomic Classification
Ichnogenus: Trypanites or Entobia / Produced by marine organisms such as bivalves, polychaetes, or jawless fish (Cyclostomata)
Morphological Description
Smooth, water-worn, oblong rock fragment featuring a prominent, clean-bored cylindrical perforation passing entirely or deeply through the body, accompanied by several smaller secondary pitting holes and surface depressions caused by bioerosion.
Rock Matrix
Calcareous sedimentary rock / limestone pebble with localized dissolution and minor secondary mineralization
Formation & Location
Coastal marine deposits, shallow shelf environments, found globally including beach deposits such as Venice Beach, Florida
Size & Dimensions
Approximately 5 to 8 cm in length, consistent with typical small marine pebble borings
Value & Rarity
Estimated Market Value
10 to 30 USD
Auction Estimate
15 to 25 USD
Rarity Assessment
Common (frequently found as beach pebbles with marine invertebrate or trace borings)
Scientific Significance
Demonstrates ancient or modern marine invertebrate/fish-substrate interactions, illustrating bioerosion patterns and shallow-marine paleoecology
Preparation Recommendations
No intensive preparation required; gentle freshwater wash and drying are sufficient. Store in a stable, dry environment.
Notable Features
The central smooth-walled perforation is exceptionally symmetrical, giving the stone an uncanny man-made appearance though formed entirely by natural marine bioerosion and mechanical tumbling.
Notes
Venice Beach