The Dinosaurs - ‘Thecocoelurus’, an Isle of Wight abelisaurid?


an Isle of Wight abelisaurid?


Sheath hollow form


7 metres (25ft)


Bonaparte & Novas, 1985

‘Thecocoelurus daviesi’ (Seeley, 1888)


Brighstone Bay

The only known specimen of ‘Thecocoelurus‘ is the anterior part of a cervical vertebra, which is projected to have been 90mm in length. This specimen shares features with oviraptorosaurs and therizinosaurs, but has no defining features of its own, but is more similar to oviraptorosaurs as therizinosauroids have more robust neural spines and slit-shaped pneumatic foramina, whereas oviraptorosaurs have rounded foramina, although this feature does also appear in some basal therizinosaurs. There has also been a suggestion that ‘Thecocoelurus‘ may have been an ornithomimid, based on similarities to Falcarius, but these are disputed, and will require further study. It has also been pointed out that the characters that apparently ‘confirm’ that ‘Thecocoelurus’ is an oviraptorsaur (low neural spine, U-shaped space between zygapophyses, hour-glass shaped centrum with ventral sulcus and ventrolateral ridges) also appear in abelisaurids, so that’s useful.

Material is rare, so please report it if you find some, as it would be nice to sort this out…

ALLAIN, VULLO, LE LOEFF and TOURNEPICHE, 2014. European ornithomimosaurs (Dinosauria, Theropoda): An undetected record. Geologica Acta. 12(2) 127-135

NAISH, D. and MARTILL, D. M. 2002. A reappraisal of Thecocoelurus daviesi (Dinosauria: Theropoda) from the Early Cretaceous of the Isle of Wight. Proceedings of the Geologists’ Association, 113, 23-30.

Naish, D. 2011. Theropod dinosaurs. In Batten, D. J. (ed.) English Wealden Fossils. The Palaeontological Association (London), pp. 526-559.