Dinosaur Egg Fragment (Incomplete Clutches)
cf. Hadrosaurid or Sauropod eggshell (taxa often identified by oospecies) • Body fossil (Hardened Eggshell) - Vertebrate (Reptilian/Dinosaurian)
Geological Period
Late Cretaceous
Estimated Age
70 to 85 million years
Preservation Type
Recrystallization and permineralization of the calcium carbonate shell structure
Condition Assessment
Fair; the specimen is a weathered fragment rather than a complete egg, with significant surface erosion and missing original perimeter
Taxonomic Classification
Phylum: Chordata, Class: Reptilia, Clade: Dinosauria, Oofamily: Spheroolithidae (likely)
Morphological Description
Specimen exhibits a dense, calcified outer surface with a characteristic 'pebbly' or tuberculated texture consistent with dinosaurian eggshell. The fragment shows some curvature, suggesting a larger spherical or ellipsoidal original form, with visible weathered fractures across the shell's exterior.
Rock Matrix
Sandy mudstone/siltstone matrix adhering to the underside; earthy-brown iron-stained coloration
Formation & Location
Commonly found in the Djadochta Formation (Mongolia), Two Medicine Formation (USA), or Nanxiong Formation (China)
Size & Dimensions
Approximately 4-6 centimeters in length; shell thickness appears to be 1.5-2.0 mm, consistent with medium-to-large herbivorous dinosaur eggs
Value & Rarity
Estimated Market Value
$40 - $120 USD
Auction Estimate
$30 - $100 USD
Rarity Assessment
Uncommon as a biological material, but relatively common as a fossil trade item compared to articulated skeletal remains
Scientific Significance
Egg remains provide vital data on reproductive strategies, nesting behavior, and the paleobiology of extinct archosaurs within their specific Cretaceous environments
Preparation Recommendations
Mechanical cleaning with air-scribes or soft brushes; stabilization with a reversible paraloid B-72 consolidant if flaky; store in a humidity-controlled environment
Notable Features
Distinctive pore patterns and surface ornamentation which are essential for ootaxonomy; the weathered appearance suggests it was found on the surface of an eroding badland formation