2025/06/01 by Gérald Mayr, Krister T. Smith · 1 voice
Earth and Planetary Sciences · Environmental Science · #Avian ecology and behavior #Evolution and Paleontology Studies #Paleontology and Evolutionary Biology
paper · doi:10.1098/rsos.250620
openalex publication_date 2025/06/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/05/21
We report the skull of a new avian species from the latest early or earliest middle Eocene fossil site Messel in Germany. Aenigmatorhynchus rarus, gen. et sp. nov. is characterized by a long, straight, and pointed beak, as well as a mandible with prominent processus coronoidei, a very long symphysis, closely adjacent cristae tomiales, and a narrow dorsal sulcus along the tip. This unusual character mosaic impedes a straightforward phylogenetic assignment. In its proportions, the mandible is superficially similar to that of extant stilts ( Himantopus , Recurvirostridae) and oystercatchers ( Haematopus , Haematopodidae), but some features preclude an assignment of Ae. rarus to these and other charadriiform taxa. The ventral ossification of the rostrum suggests comparisons with long-beaked taxa of the Aequornithes and Telluraves, but again several features conflict with a position of Ae. rarus within either of these clades. Even though an unambiguous phylogenetic placement is not possible, the new fossil expands the avifauna of the Messel site and exhibits a distinctive beak morphology, which is not found in extant birds and indicates a specialized foraging behaviour as yet unknown in birds.