NEW INFORMATION REGARDING THE HOLOTYPE OF SPINOSAURUS AEGYPTIACUS STROMER, 1915

Abstract

In the autumn of 1912, the fossil collector Richard Markgraf, with financial support and direction from Bavarian paleontologist Ernst Freiherr Stromer von Reichenbach and the Bavarian Academy of Sciences, discovered the partial skeleton of a bizarre predatory dinosaur in Upper Cretaceous (early Cenomanian, ∼97 Ma, see Ismail et al., 1989; Barakat et al., 1993; El Beialy, 1994, 1995; Nabil and Hussein, 1994; Ismail and Soliman, 2001; Ibrahim, 2002; Gradstein et al., 2005) rocks of the Bahariya Formation exposed in the Bahariya Oasis of western Egypt (Fig. 1, see also Sereno et al., 1998; Nothdurft et al., 2002). This gigantic theropod, Spinosaurus aegyptiacus Stromer, 1915, possessed highly derived cranial and vertebral features sufficiently distinct for it to be designated as the nominal genus of the clade Spinosauridae (Stromer, 1915, 1936). Spinosaurids, currently definitively known only from Europe, South America, and Africa, are important because of the scarcity of Cretaceous Gondwanan tetrapod fossils (see Krause et al., 1999, 2003; Carrano et al., 2002; Lamanna et al., 2002). Moreover, fossils of Spinosaurus Stromer, 1915 and other spinosaurids are significant because of controversy surrounding the postulated paleoecology of these taxa (see discussions in Charig and Milner, 1997; Sereno et al., 1998; Sues et al., 2002). Questions related to spinosaurid paleoecology are particularly important in the Bahariya Formation, where Spinosaurus appears to have shared its habitat (see Stromer, 1936; Smith et al., 2001) with at least two other theropods in the size range of Tyrannosaurus Osborn, 1905 ( Bahariasaurus Stromer, 1934 and Carcharodontosaurus Stromer, 1931). Unfortunately, the holotype and only known indisputable specimen of S. aegyptiacus (BSP 1912 VIII 19) was lost during the night of 24/25 April 1944 in a British bombing raid of Munich (Nothdurft et al., …