A new Archaeopteryx from the lower Tithonian Mörnsheim Formation at Mühlheim (Late Jurassic)

Here we describe a new specimen of Archaeopteryx sp. from the lower Tithonian Mörnsheim Formation in the Franconian Alb of Bavaria, Germany. This fossil is the third avialan specimen found in this formation. The skeleton comprises the right forelimb and shoulder as well as fragments of the left forelimb and both hind limbs. The lengths of the humerus and ulna are most similar to those of the Munich specimen of Archaeopteryx. Despite the specimen having been massively altered by late diagenesis, it can be referred to Archaeopteryx sp., based on the morphology of the furcula, coracoid, humerus and radius, as well as a manual ungual, which nests within the morphospace of Archaeopteryx rather than that of Anchiornis. Phylogenetic analyses also support the assignment of the new specimen to Archaeopteryx. Due to the fossil’s state of preservation, as well as the still-unresolved taxonomy of the genus Archaeopteryx on the species level, an identification beyond genus remains impossible.