A new genus and sp. of aberrant Theropoda based on remains of 2 individuals from the Trinity sands of s.-e. Okla. is descr. All important parts of the skeleton are represented and indicate an animal of exceptional size. The genus is characterized by greatly elongated and massive neural spines in allusion to which the generic name is proposed. In general, the skeletal features indicate a large rather advanced carnosaur, which, however, had not yet reached the high degree of development present in the Upper Cretaceous deinodonts. The relationships to other long-spined forms are discussed. Despite marked similarities to certain members of the Megalosauridae, the present genus appears most closely allied to the Allosauridae. The status of Altispinax is discussed.