Monoclonius
From Greek 'monos' (single) and 'klonos' (sprout or twig); meaning 'single sprout', likely referring to the single root of its teeth.
Monoclonius is an extinct dubious genus of herbivorous ceratopsian dinosaur found in the Late Cretaceous layers of the Judith River Formation in Montana, United States, and the uppermost rock layers of the Dinosaur Park Formation in Alberta, Canada dated to between 75 and 74.6 million years ago.
Species
Monoclonius crassus Cope, 1876 Nomen dubium
Type species
From Latin 'crassus' meaning 'fat' or 'thick', though the precise anatomical referent is unclear given the composite nature of the original type material.
- Holotype
- AMNH 3998 , American Museum of Natural History
- Material
- Sacrum with ten vertebrae; teeth with obliquely truncate face; femur (22 inches); tibia (20 inches); three anterior dorsal vertebrae coossified
- Horizon
- lower Judith River Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
- Locality
- mouth of Birch Creek, Montana, United States
References
- Cope, E. D. (1876). Descriptions of some vertebrate remains from the Fort Union Beds of Montana. Proceedings of the Academy of Natural Sciences of Philadelphia 28: 248-261. cope1876a
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Sampson, S. D.; Ryan, M. J.; Tanke, D. H. (1997). Craniofacial ontogeny in centrosaurine dinosaurs (Ornithischia: Ceratopsidae): taphonomic and behavioral implications. Zoological Journal of the Linnean Society 121: 293-337. Oxford University Press (OUP). doi:10.1111/j.1096-3642.1997.tb00340.x
Declares Monoclonius crassus a nomen dubium, its type a composite of immature individuals lacking diagnostic adult ornamentation.
sampson1997a -
Ryan, M. J.; Russell, A. P. (2006). The status of the problematic taxon Monoclonius (Ornithischia: Ceratopsidae) and the recognition of adult-sized dinosaur taxa. Geological Society of America Abstracts with Programs 38(4): 62.
Assessed the status of Monoclonius and the recognition of adult-sized taxa (conference abstract).
ryan2006a