Heptasteornis was no ornithominid, troodontid, dromaeosaurid or owl: the first alvarezsaurid (Dinosauria: Theropoda) from Europe

A distal tibiotarsus from the Upper Cretaceous of Sinpetru, Hateg Basin, Romania was originally described as belonging to the supposed pelecaniform bird Elopteryx but more recently various authors have proposed that it might belong to a non-maniraptoran tetanuran, ornithomimid, troodontid, dromaeosaurid or strigiform. None of these identifications withstand scrutiny. The recognition of a shared derived character and strong similarity of the specimen to the distal tibiotarsi of members of the Alvarezsauridae, a clade of controversial flightless maniraptoran theropods, leads us to suggest that it represents an alvarezsaurid. This is the first record of this group from Europe and has implications for their biogeography. The Elopteryx femora appear to belong to troodontids or pygostylians, and not to dromaeosaurids as recently argued