Open Paleo

Alcmonavis

Rauhut et al., 2019 Disputed

From Alcmona, the old Celtic name of the Altmühl River, and 'avis' (bird).

149.2–143.1 million years ago Tithonian, Late Jurassic
Late Jurassic stages

Alcmonavis is a basal genus of avialan dinosaur that during the Late Jurassic lived in the area of present Germany. The only named species in the genus is Alcmonavis poeschli. Its only known fossil was originally reported as a specimen of Archaeopteryx.

Under dispute

The validity of Alcmonavis is disputed. Rauhut, Tischlinger and Foth (2019) erected it for an isolated right wing from the Mörnsheim Formation, distinguishing it from Archaeopteryx and recovering it in a more crownward position. O'Connor and Marugán-Lobón (2026) argue that its diagnostic characters are taphonomic artifacts or ontogenetic, and that all known Solnhofen avialans represent Archaeopteryx. Foth and Rauhut (2026) accept some of those objections but retain a revised diagnosis and again recover the specimen outside Archaeopteryx.

Diagnosis

  1. Proximal part of the humerus angled at approximately 38° to the humeral shaft.
  2. Facet for the attachment of m. deltopectoralis on the deltopectoral crest of the humerus.
  3. Ulna with a well-defined, single, oval, concave proximal cotyle and a small lateral tubercle.
  4. Slender radius, with a diameter less than 0.5 times that of the ulna.
  5. Large, crest-like biceps tubercle on the proximal radius.
  6. Manual unguals with strongly developed, palmarly and transversely expanded flexor tubercles positioned close to the articular surface.
  7. Dorsal margin of manual ungual I arching higher than the proximal articular surface.
  8. Dorsal margin of manual ungual II level with the proximal articular surface.

Species

Alcmonavis poeschli Rauhut et al., 2019 Disputed

Type species

Honors Roland Pöschl, who leads the excavations at the Schaudiberg and found the specimen.

Holotype
SNSB-BSPG 2017 I 133 , Bayerische Staatssammlung für Paläontologie und Geologie
Material
Almost complete, partly disarticulated skeleton of the right wing.
Horizon
Mörnsheim Formation, Tithonian, Late Jurassic , 149.2–143.1 million years ago
Locality
Old Schöpfel Quarry, Schaudiberg, Mühlheim, Bavaria, Germany

References

  1. Rauhut, O. W. M.; Tischlinger, H.; Foth, C. (2019). A non-archaeopterygid avialan theropod from the Late Jurassic of southern Germany. eLife 8: e43789. eLife Sciences Publications, Ltd. doi:10.7554/elife.43789 rauhut2019b
  2. Foth, C.; Rauhut, O. W. M. (2026). Considerations on the taxonomy of Late Jurassic Avialae (Theropoda) from the Solnhofen Archipelago. Fossil Record 29(2): 731-758. Pensoft Publishers. doi:10.3897/fr.29.200245

    Specimen-based phylogeny and morphometrics keep Alcmonavis distinct from Archaeopteryx; source of the revised diagnosis.

    foth2026a
  3. O'Connor, J.; Marugán-Lobón, J. (2026). Evaluating variation in Solnhofen avialans. Biology Letters 22(3): 20250601. doi:10.1098/rsbl.2025.0601

    Morphometric reassessment arguing the diagnostic characters are taphonomic or ontogenetic, and that all Solnhofen avialans represent Archaeopteryx.

    o'connor2026a