The fairly complete holotype skeleton of Deltadromeus agilis (museum catalogue number SGM-Din2) measured an estimated 8 m (26.24 ft) long.
A second specimen (IPHG 1912 VIII) was originally described by Ernst Stromer as a specimen of Bahariasaurus, but was designated as a specimen of Deltadromeus by Paul Sereno in 1996. This second specimen comes from a much larger individual, with a femur (upper leg bone) length of 1.22 meters, compared to 0.74 meter femur of the holotype.
Deltadromeus skeletons have been found in the same formations as those of the giant theropods Carcharodontosaurus, Spinosaurus, and Bahariasaurus, which may be synonymous with Deltadromeus. No skull material has been found for either Deltadromeus or Bahariasaurus, and though carnivore teeth labelled as "Deltadromeus" are commonly sold in rock shops, there is no way of knowing if they actually come from this animal.
Deltadromeus is thought to have weighted up to 2 metric tons.
Deltadromeus was originally described as a large coelurosaur, but more recent studies suggest it was actually a ceratosaur, though exactly what type of ceratosaur remains unknown. One 2003 study suggested it was a member of the Noasauridae, though others have found it to be more primitive, possibly related to the primitive ceratosaurs Elaphrosaurus and Limusaurus.