a armoured thyreophoran dinosaur, walking on all fours with rows
of spikes along its back, and a large bony plate over the hips.
These were to protect it from predators. It had quite a developed
brain for an ankylosaur, and may have been quite alert and mobile.
(More info can be found at DinoWight
understand all the terminology? visit the Glossary)
the atlas and axis are separate. The dorsal surface of the presacral
centra are deeply V-shaped excavated by the neural canal; The synsacrum
consists of five dorsosacral, four sacral and one or two sacrocaudal
vertebrae. Caudal vertebrae transverse processes are present as
far as the distal third of the tail, and the chevrons are not fused
to the caudal centra. The coracoids are co-ossified to the scapula.
The supraspinous fossa is absent. The humerus has a large deltopectoral
crest that extends to midlength of the shaft; The ilium has a short,
scarcely divergent preacetabular process. The femur with distinct
lesser trochanter and fourth trochanter at the midlength of the
shaft. The tibia is 37% shorter than femur.
is quite impressive, with bilateral rows of dorso-laterally placed
conical spines along the trunk, tallest over the pectoral area,
and tall, laterally flattened, triangular-shaped, laterally placed
cervico-pectoral spines on solid, curved bases. Very noticeable
is the large flat rectangular dermal shield covering ilia and synsacrum,
ornamented dorsally with large oval ridged bosses laterally, low
round bosses medially and separated by tubercules. Large tall-spined
flattened plates extend laterally from the edges of the sacral shield.
There are bilateral rows of laterally flattened, hollow-based caudal
plates, and the distal tail ends in a bone mass composed of oval
dermal bones overlying a fused vertebral core and ventral ossified
tendons. The underside of the osteoderms show cross-hatching of
fibrous bone, and are among the most common Polacanthus material
found on the island.
is not the only ankylosaur in the Wealden, as there is the similar
Hylaeosaurus known from Sussex. However, these two may be
distinguished by the scapula and coracoid, as these are co-ossified
also a potential braincase, collected at Chilton Chine.
do I know if I've found a bone?