Fossil Dinosaur Egg
cf. Dendroolithus sp. • Body fossil (vertebrate egg)
Geological Period
Cretaceous
Estimated Age
66 to 145 million years ago
Preservation Type
Permineralization and complete mineral replacement of the original shell and internal matrix by iron oxides and sedimentary infill.
Condition Assessment
Good condition; mostly complete 3D specimen with visible surface texturing, though exhibiting some surface cracking and weathering.
Taxonomic Classification
Phylum Chordata, Class Reptilia, Clade Dinosauria, Oofamily Dendroolithidae
Morphological Description
Elongated oval shape with a distinctly textured external surface showing visible overlapping or closely packed eggshell node patterns, characterized by a network of polygonal shell units and weathering cracks across the reddish-brown surface.
Rock Matrix
Reddish-brown iron-rich sandstone and mudstone matrix.
Formation & Location
Often associated with continental red bed formations, such as the Tiantai Formation in Zhejiang Province, China, or the Hell Creek Formation in North America.
Size & Dimensions
Approximately 12 to 15 cm in length, consistent with medium-sized theropod or sauropod dinosaur eggs.
Value & Rarity
Estimated Market Value
$300 - $800 USD
Auction Estimate
$400 - $1,000 USD
Rarity Assessment
Uncommon to Rare, depending heavily on the provenance, completeness, and specific oogenus identification.
Scientific Significance
Provides crucial insights into dinosaur reproductive strategies, nesting behaviors, incubation methods, and paleobiology during the Mesozoic era.
Preparation Recommendations
Stabilization with a dilute paleontological consolidant (like Paraloid B-72) to prevent flaking of the outer shell layer; store in a stable, low-humidity environment.
Notable Features
Distinct node-like shell ornamentation and rich reddish-brown iron oxide preservation highlighting the original eggshell texture.