Theropoda: Avetheropoda: Carcharodontosaurinae

Carcharodontosaurus & Giganotosaurus

Taxa on this Page

1. Carcharodontosaurinae X
2. Carcharodontosaurus X
3. Giganotosaurini X
4. Giganotosaurus X
5. Mapusaurus X
6. Tyrannotitan X

Carcharodontosaurids are huge Allosaurid cousins that flourished in Gondwanaland (but with a few exceptions not, strangely enough, in the north). They include the largest ever land carnivores, and some even exceeded Tyrannosaurus rex in size (although not by much). The skull of carcharodontosaurids is long and narrow. Unlike the tyrannosaurs, these animals could not have possessed binocular vision if they normally looked down the length of the snout. This assumption about the direction of theropod vision may itself be flawed. Many theropods have frontated orbits, eyes which were separated only by a narrow strip of frontal. They may, therefore have looked at the world over the bridge of the nose (like humans) with the mouth directed downwards. (ATW & MAK)

Descriptions

Carcharodontosaurinae Stromer 1931 : Giganotosaurus, Carcharodontosaurus > Allosaurus

Range: Mid Cretaceous of Afr & SAm

Phylogeny: Carcharodontosauridae : (Becklespinax + Concavenator) + Kelmayisaurus + (Acrocanthosaurus + Eocarcharia + (Shaochilong + * : Tyrannotitan + (Carcharodontosaurus + Giganotosaurini)))

Characters: Very large allosauroids; maxilla with strongly rugose lateral face [CC00]; lacrimal forming low ridge anterior to orbit [CC00]; horizontal shelf of bone covering each eye; parietal forms obtuse angle with occiput [CC00]; paroccipital process with distal posterior projection [CC00]; eustachian system tripartite as in crocodiles; teeth with wrinkled enamel [CC00]; teeth not curved; horizontal undulations on compressed, blade-like teeth; undulations curved toward the tip of tooth near its cutting edges; lowest tibia / femur ratio of non-avian theropods;

Links: DD: Carcharodontosauridae; Carcharodontosaurids; Giganotosaurus - Enchanted Learning Software; Discussion of Deltadromeus and Carcharodontosaurus; g00n2a3.pdf; MEA592D Dinosaur Osteology: Lecture 4.

References: Currie & Carpenter (2000) [CC00]. ATW060214.

Comments: here used in an informal manner to refer to advanced Carcharodontosaurs, Brusatte and Sereno, 2008 us e the more limited node-based definition of Carcharodontosaurus saharicus + Giganotosaurus carolinii which unfortunately would exclude Tyrannotitan chubutensis. Since the latter is also an enormous, highly specialsed carcharodontosaur, we decided to expand the definition somewhat, perhaps this could be Carcharodontosaurus > Shaochilong or similar. MAK120303

Tyrannotitan chubutensis Novas et al., 2005

Range: Aptian of Argentina

Phylogeny: Carcharodontosaurinae : (Carcharodontosaurus + Giganotosaurini) + *

Size: length 13 meters. weight 7 tonnes

Comments: huge carcharodontosaur, closely related to but somewhat more primitive that Giganotosaurus and Carcharodontosaurus. Rather tall vertebral spines over the tail MAK120302

Carcharodontosaurus saharicus Stromer, 1931

Synonyms: Megalosaurus saharicus Deperet and Savornin, 1927, Cacharodontosaurus saharicus (Deperet & Savornin, 1927), Megalosaurus africanus Huene, 1956,

Horizon: Baharije Formation of Egypt, also known from Morocco, Algeria, Tunisia, Libya, and Niger (Early Cenomanian according to Paul 2010)

Phylogeny: Carcharodontosaurinae : Tyrannotitan + (Giganotosaurini + *)

Size: length upto 13.5 meters. weight upto 7 tonnes

Comments: As the name indicates, this animal was originally based on some shark-like teeth. Later, better material has been discovered, including, recently, a very large, nearly complete skull MAK010506 revised 1202266

Carcharodontosaurus shows some unusual convergences with the abelisaurids, another group of Gondwana theropods, specifically regarding certain features in the nature of the skull (Novas 1997b). However other features unite it with Giganotosaurus, while further cranial and postcranial character states are shared in common with Acrocanthosaurus (Holtz 2000), showing without doubt the allosaurian affinities of this species, which has only been confirmed by later cladistic analysis the unquestioned tetanurine It seems therefore that the two lineages had to evolve in similiar ways to similiar unique environmental conditions. (MAK1202266)

Giganotosaurini Coria & Currie 2006; originally Giganotosaurinae

Range: Cenomanian of Sth Am

Phylogeny: Carcharodontosaurinae : Tyrannotitan + (Carcharodontosaurus + * : Mapusaurus + Giganotosaurus)

Characters: femur with weak fourth trochanter, and a shallow, broad extensor groove on the distal end - Coria & Currie 2006

Comments: With the discovery of Mapusaurus in 2006, Rodolfo Coria and Phil Currie erected a subfamily of Carcharodontosauridae, the Giganotosaurinae, to contain the most advanced South American species, which they found to be more closely related to each other than to the African and European forms. Coria and Currie did not formally refer Tyrannotitan to this subfamily, pending a more detailed description of that genus, but noted that based on characteristics of the femur, it may be a giganotosaurine as well. (Coria & Currie 2006) - Wikipedia Other phylogenies however place Tyrannotitan as more basal to Carcharodontosaurus. We have therefore modified the rank to rank, so Giganotosaurinae becomes Giganotosaurini, and in this way can be nested in the subfamily Carcharodontosaurinae MAK120303

Mapusaurus roseae Coria & Currie 2006 (= Giganotosaurus roseae (Coria & Currie 2006)

Horizon: Huincul Formation, Río Limay Group ( Middle Cenomanian according to Paul 2010), Neuquén Province, Argentina

Phylogeny: Giganotosaurini : Giganotosaurus + *

Characters: Differs from G. carolinii in that the skull is deeper and narrower, as the maxilla is not elongate, and the nasals thick, rugose unfused and narrower (Coria & Currie 2006)

Size: 10.2 metres, 3 tonnes (Wikipedia)

Comments: Known from the remains of at least seven individuals at various growth stages discovered in a bone bed, this was a large carcharodontosaur very similar to Giganotosaurus carolinii, which lived only a few million years earlier. The tendency in dinosaur taxonomy is to make every new species a monotyal genus (although this is standard in vertebrate paleontology in general). Greg Paul is one of the very few who resists this trend (Paul 1988), although he is unsystematic in applying a multi-species approach (see Paul 2010). As it is unlikely that there would be multiple independent lineages of giant allosaurians in a single geographic region, it makes more sense that Mapusaurus is a descendent of at most a close relative of Giganotosaurus. In this case it would be better interpreted as another species of Giganotosaurus, which most likely would be the case if this was a beetle or brachiopod rather than a carcharodontosaur, although this would make the subfamily Giganotosaurinae synomous with the (non monotypal) genus Giganotosaurus. MAK120226

Giganotosaurus carolinii Coria and Salgado, 1995

Horizon: Rio Limay Formation, Neuquen, Argentina (Early Cenomanian according to Paul 2010 )

Phylogeny: Giganotosaurini : Mapusaurus + *

Size: 14 meters, weight 7 tonnes

Comments: Frequently mispelled Gigantosaurus. This is an enormous theropod, known from a partial skeleton and skull. With Carcharodontosaurus, this is the largest known land carnivore; longer and heavier than the famous Tyrannosaurus rex. It probably preyed on the huge titanosaurid sauropods with which it shared its envoronment MAK010506 revised 120226