"
Saurophaganax" skeleton (
Sam Noble Museum/
Oklahoma Museum of Natural History Facebook Reel):
It's okay, "
Saurophaganax." You can rest now (paraphrased from
Avengers Endgame, 2019).
I knew some Allosaurus bones got mixed in with the "Saurophaganax" material! I've been saying this for years. Now, a new paper written by Danison et al. states exactly what I've been saying!
Note: Download the paper. Some things in the abstract are different from what's stated in the paper.
"Saurophaganax" is officially a nomen dubium, and a chimera (pp. 81, 106, and 108). The atlas and dorsal vertebrae, and chevrons, are neosauropoda (like Camarasaurus), a diplodocid, or nomen dubium (pp. 81, 89-90, 93-95, and 108-109). Amazingly, the authors recognized that carcharodontosaurids had similar morphologies in their dorsal vertebrae compared to "Saurophaganax's" (the "Saurophaganax" holotype OMNH 1123), in particular Tyrannotitan/Giganotosaurus chubutensis and Lusovenator! I said that! However, the authors disagreed that OMNH 1123 could be definitively referred to a theropod. They didn't even know if it could accurately be assigned to a sauropod, but they decided that it probably was a sauropod that resembled Apatosaurus sp. (pp. 93 and 95). Either way, they put OMNH 1123 as a nomen dubium (pp. 95 and 108). I was right about "Saurophaganax" being a chimera! I'm also surprised that the authors also noticed a possible carcharodontosaurid connection to "Saurophaganax!"
Atlas vertebrae of
Allosaurus jimmadseni (A), "
Saurophaganax" (B), and
Camarasaurus sp. (C) (p. 89 Figure 4):
"
Saurophaganax" holotype OMNH 1123 (A) compared to
Apatosaurus sp. OMNH 1366 (B). The sprl in
Apatosaurus sp. seem to match the al in "
Saurophaganax" (p. 94 Figure 8):
See p. 93 for the comparison between the laminae of the two bones. I wonder... Are the laminae in OMNH 1123 so wide because the specimen was a hatchling, or juvenile? If the animal grew, would the laminae become elongated like Apatosaurus' are? That's just a guess though.
The Allosaurus material was either named Allosaurus anax, or Allosaurus sp. (pp. 82-83, 106-109). The giant humerus, OMNH 1935, which I thought had to be Allosaurus, was "indistinguishable from that of Allosaurus fragilis and Allosaurus jimmadseni." The authors said it was an allosaurid, despite it's great size (pp. 100-101, and 106), but for some reason they didn't put it as Allosaurus anax or Allosaurus sp. Since the authors agreed with me that OMNH 1935 was basically Allosaurus, I'll put the giant humerus as Allosaurus sp. myself.
Originally, I put the femora in Allosaurus, but switched to putting it in "Saurophaganax." I also put the tibiae in "Saurophaganax." It turns out that the femora were Allosaurus after all, but not A. fragilis or A. jimmadseni. The authors called it Allosaurus sp. (pp. 102 and 109). The tibiae were also assigned to Allosaurus sp. (pp. 104 and 109). The postorbital, a cervical vertebra, two dorsal centrum, and fibulae, were assigned to Allosaurus anax and not "Saurophaganax" (pp. 82-83, and 108-109). The metatarsals, which I thought were either Allosaurus or a carcharodontosaurid, were put under Allosaurus sp. (pp. 106 and 109). I was VERY conservative in estimating how much of the "Saurophaganax" material belonged to Allosaurus! That is shocking!
Speaking of Allosaurus maximus, it's a synonym of "Saurophaganax maximus" because it used the specimen OMNH 1123 as the holotype. That's probably the reason why Allosaurus anax was erected as the new genus name, along with the fact that the authors see the Allosaurus material as distinct from A. fragilis and A. jimmadseni (p. 107).
"Saurophaganax" was a chimera (like I've stated before), and a nomen dubium. "Saurophaganax" wasn't even a carcharodontosaurid, like I originally hypothesized. It probably didn't even exist! However, I'm just glad that I was right about the Allosaurus bones being lumped into the "Saurophaganax" material. Heck, almost all of the bones were Allosaurus sp. or Allosaurus anax! I wasn't going far enough! However, it's good to double-check and be cautious at times.
Vindication, once again! Nanotyrannus is a basal tyrannosauroid, and the holotype was an adult specimen with an EFS in its hyoid bone! Now, "Saurophaganax" is a confirmed chimera and had Allosaurus bones in it!
