Sasayamagnomus
Named for the Sasayama Basin in Hyōgo Prefecture, Japan, where the fossils were found, combined with Latin 'gnomus' meaning 'gnome'; meaning 'gnome from Sasayama.'
Early Cretaceous stages
Sasayamagnomus is an extinct genus of neoceratopsian dinosaur from the Early Cretaceous (Albian age) Ohyamashimo Formation of Hyōgo Prefecture, Japan. The genus contains a single species, Sasayamagnomus saegusai. The holotype individual is estimated to reach 80 centimeters (2.6 ft) long, although this specimen is not fully grown.
Diagnosis
- Jugal with pronounced caudally expanded articular surface for the squamosal
- Cranially oriented medial process of the squamosal with an acute angle (~10°) relative to the rostral process
- Coracoid with prominent biceps tubercle on the lateral surface
- Lacrimal with unique combination: fungiform dorsal expansion, prominent ridge at ventral margin, and deep antorbital fossa
Species
Sasayamagnomus saegusai Tanaka et al., 2024
Type species
Named for Haruo Saegusa, a paleontologist who led dinosaur excavations in the Tamba area and made significant contributions to vertebrate paleontology in Hyogo Prefecture, Japan.
- Holotype
- MNHAH D1-060516 , Museum of Nature and Human Activities
- Material
- Left lacrimal, left jugal, left quadrate, left quadratojugal, and left squamosal.
- Horizon
- Ohyamashimo Formation, Albian, Early Cretaceous , 113.2–100.5 million years ago
- Locality
- Miyada microvertebrate site, Hyōgo, Japan
References
- Tanaka, T.; Chiba, K.; Ikeda, T.; Ryan, M. J. (2024). A new neoceratopsian (Ornithischia, Ceratopsia) from the Lower Cretaceous Ohyamashimo Formation (Albian), southwestern Japan. Papers in Palaeontology 10(5). Wiley. doi:10.1002/spp2.1587 tanaka2024a