(collar of spikes).
Named By: Susannah C. R. Maidment, Sarah J. Strachan, Driss Ouarhache, Torsten M. Scheyer, Emily E. Brown, Vincent Fernandez, Zerina Johanson, Thomas J. Raven & Paul M. Barrett - 2021
Classification: Chordata, Dinosauria, Ornithischia, Thyreophora, Ankylosauria.
Species: S. afer (type).
Size: Unknown due to lack of remains.
Known locations: Morocco - El Mers Group.
Time period: Bathonian-Callovian of the Jurassic.
Fossil representation: Single rib.
described from a single rib, the dinosaur Spicomellus
has generated a
lot of interest. First is the original assessment that Spicomellus
represents a primitive ankylosaur,
and if true this would not only
help to build a pattern of development of this dinosaur lineage all the
way back into the Jurassic, something suspected, but difficult to
piece together. The second bit of excitement about the genus is the
rib itself, and the fact that four ossified spines are fused to it.
Indeed, when the specimen first came to the attention of
palaeontologists it was first thought to represent a fake, but CT
scanning suggested it was actually genuine.
because the spines are fused to the rib this marks Spicomellus as being different from later ankylosaurs where bony plates and spines are not attached to the actual skeleton but ‘float’ in dermal tissues such as skin and muscle. Why they were fused in Spicomellus, we don’t yet know. They were probably for defence, but also a development that may have reduced the mobility of the animal.
If Spicomellusis does indeed represent a primitive ankylosaur, it would be the first dinosaur of its kind known from the African continent.
- Bizarre dermal armour suggests the first African ankylosaur. - Nature Ecology & Evolution. 5 (12): 1576–1581. - Susannah C. R. Maidment, Sarah J. Strachan, Driss Ouarhache, Torsten M. Scheyer, Emily E. Brown, Vincent Fernandez, Zerina Johanson, Thomas J. Raven & Paul M. Barrett - 2021.