Albertosaurus olseni, Gilmore, 1933

Paul, G. S., 1988, Predatory Dinosaurs of the World, Predatory Dinosaurs of the World, New York: Touchstone Books, pp. 323-349 : 328

ALBERTOSAURUS? (ALECTROSAURUS?) OLSENI (Gilmore, 1933)

synonym— Alectrosaurus olseni

type— AMNH 6554

time—early? Late Cretaceous

horizon and distribution—Iren Dabasu Formation of Mongolia

	Type
SKULL LENGTH— —	~ ~600 600 mm mm
TOTAL LENGTH— —	~ ~5 5 m m
KILOGRAMMAGE— —	~ ~500 500??

This poorly known species has a number of uncertainties about it. It is usually placed in its own genus because of the enormous forelimb bones found with the very incomplete type specimen. I am very skeptical about these forelimbs, however, because they look very like those of Therizinosaurus and segnosaurs, which are also in Mongolia. In fact, more recent finds assigned by Perle in 1977 to A. olseni show a typically slender tyrannosaur shoulder blade that could not support such a big arm. Perle drew a nearly complete skull reconstruction which, although too schematic to adapt for use here, is very like other albertosaurs, including the short teeth. It also lacks Alioramus’s peculiar nasal ridge. The hind limb is long and in most ways A Albertosaurus-like /bertosaurus-like.. All in all, this looks like a small, primitive Asian albertosaur, primitive enough that it may be its own subgenus, or even genus, Alectrosaurus. It hunted the segnosaurs, protoceratopsids, and juvenile hadrosaurs in its area.