Lord of the Spinosaurs
MemberCompsognathusDecember 24, 2014As we all know there have been many predators discovered in the “middle Cretaceous” of Northern Africa, in fact it seems we have discovered to many (Stromer’s riddle). Though which one was the top predator? Here is a list of candidates:
- Spinosaurus
- Carcharodontosaurus
- Bahariasaurus
- Sauroniops
- Sigilmassasaurus
- Deltadromeus
- Suchomimus
- Eocarcharia
Note: all of the predators above are about the length of Tyrannosaurus or longer.
We will go through each and every one of those predators and determine if they were possibly the top predator of the most dangerous environment in the history of the Earth. Lets begin.
Spinosaurus: Although it was big, I think it is safe to assume that Spinosaurus was not the top predator on the land due to its aquatic adaptations. Though in the water it may have been the top predator competing with animals like Sarcosuchus and Kronosaurus.
Carcharodontosaurus: Carcharodontosaurus was probably the largest land-adapted Theropod in Cretaceous North Africa tied with a later Theropod on this list. In terms of abilities Carcharodontosaurus was nothing out of the ordinary, basically Carcharodontosaurus is a good example for a large Theropod Dinosaur due to the fact that it is not specialized unlike Spinosaurus and Tyrannosaurus. Although it may have hunted in small gangs like its relative Giganotosaurus.
Bahariasaurus: Bahariasaurus was probably tied with Carcharodontosaurus as the largest land-adapted Theropod in Cretaceous North Africa. Personally, I believe Bahariasaurus was a basal Tyrannosaur (Tyrannosauroid). I think that Bahariasaurus was tied with Tyrannosaurus as the largest Tyrannosauroid, although I don’t expect anybody to agree with me. This would mean that Bahariasaurus had a large bite force (probably not as large as T-Rex though larger than all other African Theropods), this would also mean that Bahariasaurus was smart for a large Theropod(probably as smart as T-Rex). All of these typical Tyrannosaur adaptations would give Bahariasaurus an advantage over its main competitor Carcharodontosaurus. Though I find it unlikely that Bahariasaurus hunted in small gangs unlike Carcharodontosaurus and its South American relatives Giganotosaurus and Mapusaurus.
Sauroniops: Due to the fact that the only fossil we have of Sauroniops suggests an animal slightly smaller than Carcharodontosaurus and Bahariasaurus, I find it unlikely that it was the top predator. Though this is only one individual, so until further finds are announced I am saying that Sauroniops was not the top predator of the most dangerous place in the history of Earth.
Sigilmassasaurus: The finds we have of Sigilmassasaurus suggest an animal slightly smaller than Carcharodontosaurus and Bahariasaurus just like Sauroniops. Also, since I believe Sigilmassasaurus was a Neovenatorid this would probably make it slightly more agile than Carcharodontosaurus and Sauroniops. Though as of right now I am saying that Sigilmassasaurus is not the top predator until further finds are announced just like Sauroniops.
Deltadromeus: I find it highly unlikely that Deltadromeus was the top predator. Deltadromeus weighed about 1 ton yet in terms of volume it was the size of Tyrannosaurus Rex. This suggests an extremely lightly built Theropod, combined with its long and strong legs it probably took the role of a modern-day Cheetah.
Suchomimus: Just like its relative Spinosaurus I think it is safe to assume that Suchomimus was not the top predator due to the fact that it was adapted to a more aquatic lifestyle. Although it had strong hindlimbs (unlike Spinosaurus) and large claws which it could probably use to defend itself, its Crocodile-like snout suggests a more fishy diet.
Eocarcharia: Just like Sauroniops and Sigilmassasaurus, the finds we have suggest an animal slightly smaller than Carcharodontosaurus and Bahariasaurus. Until further finds are announced I am saying that Eocarcharia was not the top predator.
So yeah, it all comes down to Carcharodontosaurus and Bahariasaurus, and it really depends on whether or not Carcharodontosaurus hunted in gangs or not. Maybe they were like Lion and Hyena or the Asiatic Lion and the Bengal Tiger (that was until us, humans, separated those two big cats from each other).
Anyways, tell me who you think was the top predator, Carcharodontosaurus or Bahariasaurus or maybe another Theropod on the list. Thanks!
There is no such thing as a pure predator. A meat-eater is eit
S. Tenerensis & E. dinops are from the "lower" cretaceous and did not coexist with the rest of theropods listed on that list.
Carcharodontosaurus - Not much to say on this one. 11-13 meters in length, 6 - 8 tons in weight it is, in my opinion, the dominant land carnivore of the time. Made moreover worse for whatever it ate if C. saharicus hunted in packs.
Sigilmassasaurus - Was found synonymous with S. aegyptiacus in Ibrahim et. al 2014.
"...Although hundreds of isolated bones and teeth of S. aegyptiacus are in collections around
the world, a few specimens are more complete and thus have garnered attention.
“Spinosaurus B”. Stromer designated bones found in close association as “Spinosaurus
B” (2), a partial skeleton that was entirely destroyed in WWII. The unusual proportions
of the neotype (reduced pelvis size and short hind limb length compared to the axial 10
column) are also present (and nearly identical) in this specimen (fig. S2), suggesting that
it composed a second associated individual of S. aegyptiacus."
Spinosaurus - Due to new finds, we now know S. aegyptiacus was vastly adapted for semi-aquatic life style. It was, clearly, the dominant predator of its realm with competition from the larger species of crocodilians.
Sauroniops - This is where it gets interesting.
^ that's all we have for this carcharodontosaurid.
Here's something interesting i've found researching this creature..
" Phylogenetic analysis found robust support for placing Sauroniops among the basal carcharodontosaurids and related to Eocarcharia, showed that some of the unusual features of the new theropod were convergently acquired by abelisaurids, and revealed a mosaic pattern in the evolution of the carcharodontosaurid skull table. The frontals of Sauroniops and Carcharodontosaurus, both from the ‘Kem Kem compound assemblage’ of Morocco, show comparable size but differ in the extent of the naso–frontal articulation, the shape and disposition of the prefrontal and lacrimal articulations, the development of dorsal ornamentation and the morphology of the supratemporal fossa. Among carcharodontosaurids, the skull table developed unique configurations among each lineage and appears diagnostic at the species-level. The dome-like frontal in Sauroniops may indicate head-butting behaviour in this taxon or evolved for visual display."
Basing off of Eocarcharia Dinops, we get ~11.6 meters in length, ~4 tons -- in other words the size range of A. atokensis. Based on phylogeny this doesn't suprise me. It was probably only under C. saharicus in terms of dining order.
Deltadromeus - Was a primative ceratosaur that was very likely low on the food chain.
"The poorly known theropod Deltadromeus agilis was first
described as a primitive coelurosaur (Sereno et al. 1996) and
later placed in the Ornithomimosauria (Rauhut 2000, 2003).
However, more recently it has been placed within Ceratosauria
(Carrano & Sampson 2002, 2004; Sereno et al. 2004),
a conclusion supported by features in the limbs and girdles.
Although Deltadromeus was resolved as a noasaurid based
on two synapomorphies (Wilson et al. 2003; Sereno et al.
2004), our analysis does not support this conclusion. Instead,
Deltadromeus is a primitive ceratosaur with possible affinities
to Elaphrosaurus and Spinostropheus; 12 extra steps are
needed to place it within Noasauridae."
Based on its phylogenic positioning in Noasauridae, it's safe to assume this creature was rather minute in overall stature ~6-7 meters, 1,500 lbs. Scaling from Elaphrosaurus and Spinostropheus duplicated these results.
Bahariasaurus - Too fragmentary to really tell at the moment, It's now known to not be synonymous with D. agilis -- something commonly accepted in the early 2000's.
What has been suggested for B. Ingens, is that it be placed within Ornithomimosauridae. But, again, the material is too fragmentary and we don't have the actual fossils to work with. But, if it was an Ornithomimian it was certainly not at the top of its food chain -- rather towards the bottom.
Sources:
The Phylogeny of Ceratosauria(Dinosauria: Theropoda)(Caranno & Sampson 2008)
A thick skulled theropod from the (Dinosauria, Saurischia) from the Upper Cretaceous of Morocco with the implications for Carcharodontosaurid cranial evolution (Cau 2012)
Supplementary materials for semiaquatic adaptations in a giant predatory dinosaur (Ibrahim, Sereno 2014)
Nature doesn't deceive us; it is we who deceive ourselves.
