Invictibellatrix

Artists’ rendition of Invictibellatrix amberina with contemporary fauna in the lower part of the Wessex Formation.

Stratigraphical distribution of known dinosaurian fauna across the Wessex Formation spread, split into the three dinosaurian clades: theropods, ornithischians and sauropods to determine faunal assemblage diversity and sympatry across the Wessex Formation (see supplementary material for full details of taxa locations). The black silhouette represents the stratigraphical location of Invictibellatrix. Silhouettes by Daniel D. Folkes.

Invictibellatrix is a megaraptoran theropod that lived during the Early Cretaceous period in what is now England. It is the first megaraptoran discovered in Europe, shedding light on how this group diversified and dispersed throughout the Cretaceous. Invictibellatrix is the smallest known megaraptoran, at an estimated 3-4 m in total body length.

Speculative life restoration of Invictibellatrix amberina, the first megaraptoran dinosaur described from Europe, based off of T.K. Robinson’s composite megaraptoran skeletal: https://incinerox.artstation.com/projects/J9aV0d

Photographs of the holotype braincase (NHMUK PV R6775) of I. amberina in A: anterior, B: posterior; C: right lateral; D: left lateral; E: ventral; F: dorsal views. Abbreviations: atr, anterior tympanic recess; boc, basioccipital crest; bpr, basipterygoid recess; bsr, basisphenoid recess; bt, basal tubera; btw, basituberal web; CN, cranial nerves V, VII; cp, cultriform process; cvl, crista ventrolateralis of basisphenoid; fm, foramen magnum; oc, occipital condyle; ova, fenestra ovalis; pcr, paracondylar recess; pit, depression of the pituitary gland within the pituitary fossa; pp, paraoccipital process; prp, preotic pendant; psncr, parasagittal nuchal crest recess; scr, sub-condylar recess; snc, parasagittal nuchal crest; sok, supraoccipital knob; sta, sella turcica. Scale bar equals 50 mm.

Line drawings of the holotype braincase (NHMUK PV R6775) of I. amberina in A: anterior, B: posterior; C: right lateral; D: left lateral; E: ventral; F: dorsal views. Abbreviations: atr, anterior tympanic recess; boc, basioccipital crest; bpr, basipterygoid recess; bsr, basisphenoid recess; bt, basal tubera; btw, basituberal web; CN, cranial nerves V, VII; cp, cultriform process; cvl, crista ventrolateralis of basisphenoid; fm, foramen magnum; oc, occipital condyle; ova, fenestra ovalis; pcr, paracondylar recess; pit, depression of the pituitary gland within the pituitary fossa; pp, paraoccipital process; prp, preotic pendant; psncr, parasagittal nuchal crest recess; scr, sub-condylar recess; snc, parasagittal nuchal crest; sok, supraoccipital knob; sta, sella turcica. Scale bar equals 50 mm.

Photographs (left) and line drawings (right) of the holotype braincase (NHMUK PV R6775) of Invictibellatrix amberina in A: anterior, B: posterior; C: right lateral; D: left lateral; E: ventral; F: dorsal views. Abbreviations: atr, anterior tympanic recess; boc, basioccipital crest; bpr, basipterygoid recess; bsr, basisphenoid recess; bt, basal tubera; btw, basituberal web; CN, cranial nerves V, VII; cp, cultriform process; cvl, crista ventrolateralis of basisphenoid; fm, foramen magnum; oc, occipital condyle; ova, fenestra ovalis; pcr, paracondylar recess; pit, depression of the pituitary gland within the pituitary fossa; pp, paraoccipital process; prp, preotic pendant; psncr, parasagittal nuchal crest recess; scr, sub-condylar recess; snc, parasagittal nuchal crest; sok, supraoccipital knob; sta, sella turcica. Scale bar equals 50 mm.