Monoclonius
| Monoclonius | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temporal occurrence | ||||||||||||
| Upper chalk | ||||||||||||
| 75 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Monoclonius | ||||||||||||
| Cope , 1876 |
Monoclonius is a controversial genus of pelvic dinosaurs from the group of Ceratopsidae .
There are numerous fossil finds that were led under the name " Monoclonius ", many of them are often badly preserved individual bones. Most of the finds today are assigned to other genera, such as Centrosaurus or Styracosaurus, or are considered nomina dubia , which means that they are too sparse for a precise systematic classification.
The genus, now listed as Monoclonius , with the only species M. crassus, is characterized by a thin neck shield, the edge of which, unlike other Centrosaurinae, was smooth and not provided with horns. The finds come from non-adult animals, however, and since the diagnostic features of the Ceratopsidae in the construction of the horns and the neck shield were only shown in adult animals, it is conceivable that Monoclonius are juveniles of another, already known genus. Some authors therefore generally regard Monoclonius as an invalid name. The often found representation with a long nasal horn comes from a find that is now attributed to Styracosaurus .
Monoclonius was one of the oldest known Ceratopsidae, it was first described by Edward Drinker Cope in 1876 . The finds come from the Judith River Group in the US state of Montana , possible other finds come from Alberta ( Canada ). The generic name means “a branch” or “a scion” and does not allude to the nasal horn, but to the structure of the teeth. The finds are dated in the Upper Cretaceous (late Campanian ) to an age of around 75 million years.
literature
- Peter Dodson , Catherine A. Forster, Scott D. Sampson: Ceratopsidae. In: David B. Weishampel , Peter Dodson, Halszka Osmólska (eds.): The Dinosauria . 2nd edition. University of California Press, Berkeley CA et al. 2004, ISBN 0-520-24209-2 , pp. 494-513.
