Invictibellatrix

Invictibellatrix; Temporal range: Early Cretaceous, Barremian PreꞒ Ꞓ O S D C P T J K Pg N
	Photographs (left) and line drawings (right) of the holotype specimen
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Clade:	†Megaraptora
Genus:	†Invictibellatrix; Morrison et al., 2026
Species:	†I. amberina
Binomial name
	†Invictibellatrix amberina; Morrison et al., 2026

Invictibellatrix is an extinct genus of megaraptoran theropod dinosaur known from the Early Cretaceous (Barremian age) Wessex Formation of England. The genus contains a single species, Invictibellatrix amberina, known from a single braincase. Invictibellatrix is estimated to have a body mass between 200–300 kg (440–660 lb) and a body length of around 4 m (13 ft).

Discovery and naming

The Invictibellatrix fossil material was discovered in outcrops of the Wessex Formation on the Isle of Wight, United Kingdom. The specimen is housed in the Natural History Museum in London, where it is permanently accessioned as specimen NHMUK PV R 6775. It was sold to the museum in May 1924 by the widow of the collector Reginald Walter Hooley. It consists of an isolated braincase (part of the skull that houses the brain). Prior to the formal naming of Invictibellatrix, the fossil material was reported in a conference abstract in 2024. In 2026, Cassius Morrison and colleagues described Invictibellatrix amberina as a new genus and species of megaraptoran theropod based on these fossil remains, designating NHMUK PV R 6775 as the holotype specimen.

References

1 2 3 Morrison, Cassius; Scherer, Charlie Roger R.; Mannion, Philip; Porro, Laura B.; Clark, Brett; Folkes, Daniel D.; Barrett, Paul M. (2026-09-16). "A new megaraptoran dinosaur from the Lower Cretaceous Wessex Formation, UK, and its implications for theropod evolution and biogeography". Royal Society Open Science. 13 (10) 260937. doi:10.1098/rsos.260937.
↑ Morrison, C. D. I.; Perkins, J.; Scherer, C.; Mannion, P. D.; Porro, L. B.; Clark, B.; Barrett, P. M. (2024). The first reported megaraptoran theropod dinosaur from Europe and the implications for megaraptoran origins (PDF). 21st Conference of the European Association of Vertebrate Palaeontologists. pp. 37–38.

[Invictibellatrix-1] 1 2 3 Morrison, Cassius; Scherer, Charlie Roger R.; Mannion, Philip; Porro, Laura B.; Clark, Brett; Folkes, Daniel D.; Barrett, Paul M. (2026-09-16). "A new megaraptoran dinosaur from the Lower Cretaceous Wessex Formation, UK, and its implications for theropod evolution and biogeography". Royal Society Open Science. 13 (10) 260937. doi:10.1098/rsos.260937.

[EAVP2024-2] Morrison, C. D. I.; Perkins, J.; Scherer, C.; Mannion, P. D.; Porro, L. B.; Clark, B.; Barrett, P. M. (2024). The first reported megaraptoran theropod dinosaur from Europe and the implications for megaraptoran origins (PDF). 21st Conference of the European Association of Vertebrate Palaeontologists. pp. 37–38.