Within Carnosauria, there is a slightly more exclusive clade, superfamily
Allosauroidea. The
clade Allosauroidea was originally named by
Othniel Charles Marsh, but it was given a formal definition by
Phil Currie and Zhao, and later used as a
stem-based taxon by
Paul Sereno in 1997. Sereno was the first to provide a stem-based definition for the Allosauroidea in 1998, defining the clade as "All neotetanurans closer to
Allosaurus than to
Neornithes."
Kevin Padian used a node-based definition in his 2007 study which defined the Allosauroidea as
Allosaurus,
Sinraptor, their
most recent common ancestor, and all of its descendants.
Thomas R. Holtz and colleagues and
Phil Currie and
Ken Carpenter, among others, have followed this node-based definition. Depending on the study, Carnosauria and Allosauroidea are sometimes considered synonymous. In such cases, several researchers have elected to use Allosauroidea over Carnosauria.
Conventional phylogeny The following
cladogram illustrates the phylogenetic position of Allosauroidea within Theropoda. It is a simplified version of the tree presented in a synthesis of the relationships of the major theropod groups based on various studies conducted in the 2010s. The ⊞ button can be clicked to expand the clade and display the interrelationships of the four major allosauroid groups.
Alternative hypotheses The composition of the clade Carnosauria has been controversial among scientists since at least
2010. Different clades have been recovered by different authors, and a scientific consensus has yet to emerge. One such clade is
Neovenatoridae, a proposed clade of
carcharodontosaurian carnosaurs uniting some primitive members of the group such as
Neovenator with the
Megaraptora, a group of theropods with controversial affinities. Other studies recover megaraptorans as basal
coelurosaurs unrelated to carcharodontosaurs. Other theropods with uncertain affinities such as
Gualicho,
Chilantaisaurus and
Deltadromeus are also sometimes included. Neovenatoridae, as formulated by these authors, contained
Neovenator,
Chilantaisaurus, and a newly named clade: Megaraptora. Megaraptora contained
Megaraptor,
Fukuiraptor,
Orkoraptor,
Aerosteon, and
Australovenator. These genera were allied with the other neovenatorids on the basis of several features spread out throughout the skeleton, particularly the large amount of pneumatization present. The pneumatic ilium of
Aerosteon was particularly notable, as
Neovenator was the only other taxon known to have that trait at the time. Neovenatorids were envisioned as the latest-surviving allosauroids, which were able to persist well into the Late Cretaceous due to their low profile and coelurosaur-like adaptations. and Zanno & Makovicky description of the newly discovered theropod
Siats in 2013, which they placed within Megaraptora.
Fukuiraptor and
Australovenator were consistently found to be close relatives of each other; this was also the case for
Aerosteon and
Megaraptor.
Orkoraptor was a
"wildcard" taxon difficult to place with certainty. Phylogenetic studies conducted by Benson, Carrano and Brusatte (2010) and Carrano, Benson and Sampson (2012) recovered the group
Megaraptora and a few other taxa as members of the Neovenatoridae. This would make neovenatorids the latest-surviving allosauroids; at least one megaraptoran,
Orkoraptor, lived near the end of the
Mesozoic era, dating to the early
Maastrichtian stage of the latest
Cretaceous period, about 70 million years ago. }} Subsequent analyses have contradicted the above hypothesis. Novas and colleagues conducted an analysis in 2012 which found that
Neovenator was closely related to carcharodontosaurids, simultaneously found
Megaraptor and related genera to be
coelurosaurs closely related to
tyrannosaurids. However, Novas
et al. subsequently found that megaraptorans lacked most of the key features in the hands of derived coelurosaurs including
Guanlong and
Deinonychus. Instead, their hands retain a number of primitive characteristics seen in basal tetanurans such as
Allosaurus. Nevertheless, there are still a number of other traits that support megaraptorans as members of the Coelurosauria. Other taxa like
Deltadromeus and
Gualicho have been alternatively recovered as coelurosaurs or
noasaurid ceratosaurs. Several recent analyses do not find a relationship between
Neovenator and megaraptorans, which suggests that the latter were not carnosaurs or allosauroids. As a result of these findings, and the fact that
Neovenator itself is the only uncontroversial neovenatorid, the family Neovenatoridae sees little use in recent publications. }} }} In 2025, photos of a destroyed specimen of
Carcharodontosaurus were re-examined by Maximilian Kellermann and colleagues and were used to erect the new genus
Tameryraptor. A byproduct of this study was the recovery of a novel phylogenetic arrangement of carnosaurs. They did not recover megalosauroids as close relatives of allosauroids. Within Allosauroidea, their analyses, based on the dataset published by Wang and colleagues in 2017, consistently found
Metriacanthosauridae and
Carcharodontosauridae as
sister taxa. They named this novel clade
Carcharodontosauriformes and defined it as the least-inclusive clade containing both
Carcharodontosaurus and
Sinraptor. A simplified version of one of the cladograms they published are shown below. }} }} }} }} }} }} == Paleobiology and behavior ==