Misidentified Species Guide

Common fossils labeled as rare. Marine reptiles sold as dinosaurs. Modern bone stained as Ice Age. The most common species fraud.

Spinosaurus Tooth Sold as T-Rex

Most common misidentification. Spinosaurus teeth are abundant ($10-50). T-Rex teeth rare ($500-5,000+). Spinosaurus: conical, unserrated, round cross-section. T-Rex: serrated, blade-like, D-shaped cross-section. Serrations are distinct under magnification.

Mosasaur Tooth as Dinosaur Tooth

Mosasaur was a marine reptile, not a dinosaur. Teeth common in Morocco ($5-30). Real dinosaur teeth far rarer. Mosasaur: conical, curved, two cutting edges (anterior and posterior carinae) with fine serrations on some genera. Dinosaur teeth: heavier serrations, blade-like cross-section, and distinct wear facets that marine reptiles lack.

Common Trilobite as Rare Species

Flexicalymene/Phacops are abundant. Dicranurus/Ceratarges are rare and valuable. Check: spine count, glabella shape, pygidium detail. Cross-reference with trilobite catalogs. Too-good-to-be-true price = common species.

Crocodile Tooth as Dinosaur Tooth

Fossil crocodile teeth abundant and cheap. Dinosaur teeth rare. Crocodile: conical, smooth, round. Dinosaur: serrations, carinae (cutting edges), wear facets. Almost no crocodilian has serrations.

Modern Bone as Fossil

Modern bone stained/heat-treated to look fossilized. Burn test: fossilized bone doesn't burn or smell organic. Modern bone chars. Fossils are mineralized — feel like stone, not bone.

Common Ammonite as Rare Species

Perisphinctes/Cleoniceras abundant ($10-50). Heteromorphs (Nipponites) rare. Check: shell shape (coiled vs irregular), suture complexity, rib density. Cross-reference guides.

Composite as Articulated Skeleton

Loose bones glued together, sold as articulated. Real bones but from different individuals or species. Check: mismatched color, different preservation, unnatural angles, inconsistent proportions.

Wrong Formation / Region Swap

Formation matters for value. T-Rex from Hell Creek vs 'T-Rex with no locality.' Sellers omit or fabricate location data. Always demand formation and county-level locality.

Proposed listing controls

— Require the seller's proposed scientific identification and confidence level.

— Show the evidence and reviewer identity when a specialist opinion exists.

— Never turn an algorithmic suggestion into a verified species claim.

— Let buyers report suspected misidentification for documented review.

Defense Guide