Article
Extended Data Fig. 4 | Rendering of the cranial endocast of HPG-15-3.
a, Dorsal view. b, Ventral view. c, Caudal view. d, Cranial view. e, Right lateral
view. f, Left lateral view. g, Interior view of the brain cavity, showing the bivalve
boring that intrudes through the ventral surface. Because the ventral surface of
the cranium is damaged by a bivalve boring and the bones supporting the
cranial margins of the brain are not preserved, only the dorsal surface of the
endocast reveals reliable information. The white dashed lines indicate the
portions of the endocast that probably were not occupied by brain tissue. The
cerebrum appears to be prominent but a distinct optic lobe—as seen in other
birds—cannot be identified. bb, bivalve boring; c, cerebrum; ot, part of the
olfactory tract and/or olfactory lobe.