can be compared with Thecocoelurus daviesi and Calamosaurus foxi, both of which were erected for cervical vertebrae (Seeley, 1888; Lydekker, 1889). The presence of one well-preserved cervical neural arch of Eotyrannus allows comparison with these forms. BMNH R181, the incomplete holotype cervical vertebra of Thecocoelurus daviesi, has a distinc- tive hourglass-shaped ventral sulcus and ventrolateral raised edges. In these features and others (absent from the vertebrae of Eotyrannus) T. daviesi is reminiscent of the cervical vertebrae of Chirostenotes pergracilis (Sues, 1997) and probably represents an oviraptoro- saur (Naish, 1999a; Naish R Martill, submitted). It is clear that Eotyrannus is not an oviraptorosaur and therefore synonymy with T. daviesi is improbable. The cervical neural arch known for Eotyrannus differs from that of Calamosaurus in having robust postzygapophy- ses that project markedly laterally and in lacking the distinctive square-shaped diapophyses of this taxon (Naish, 1999a). However, the Calamosaurus material does not include an axis.

Eotyrannus clearly has no close affinity with the large spinosauroid Baryonyx or with the allosauroids Neovenator or Bechlespinax. Ornithodesmus cluniculus and Aristosuchus pusillus are both based on sacra and parts of the pelvis. Sacral vertebrae of both O. cluniculus and A. pusillus lack the ventral keel seen in Eotyrannus (Howse R Milner, 1993). A. pusillus also lacks pleurocoels on its sacral vertebrae. Furthermore, O. cluniculus is reminiscent of coelophysoids and abelisauroids and may not be a tetanuran while A. pusillus appears to represent a compsognathid (Naish, 1999c).

Phylogenetic position of Eotyrannus