A nearly complete Archaeopteryx skeleton exposes a mosaic of avialan and non-avian theropod features.
Represented range150–148 Ma
RegionsSolnhofen Archipelago, Bavaria, Germany
CladesArchaeopteryx · Avialae
Claim ledger
morphology · medium
The nearly complete Thermopolis Archaeopteryx specimen, later catalogued WDC CSG 100, preserves a hyperextendible second toe, a tetraradiate palatine and a hallux unlike a fully reversed perching toe; this anatomical mosaic supports theropod affinity without proving direct ancestry or a unique first bird.