[2] Distinctive characteristics of carnosaurs include large eye sockets, a long narrow skull and modifications of the legs and pelvis such as the thigh (femur) being longer than the shin (tibia).

However, it has been noted that these may be sauropod scales due to their similarity and the fact that non-theropod remains were discovered associated with the tail of this particular Allosaurus specimen.

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.

"[22] 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.

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.

[26] Coelophysoidea Dilophosauridae Ceratosauria Megalosauroidea Carnosauria / Allosauroidea Tyrannosauroidea Compsognathidae Maniraptora The cladogram presented below illustrates the interrelationships between the four major groups (or families) of carnosaurs.

It is a simplified version of the tree presented in the 2012 analysis by Carrano, Benson and Sampson after they excluded three "wildcard" taxa Poekilopleuron, Xuanhanosaurus, and Streptospondylus.

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.

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.

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.

[25][13] The cladogram below follows a 2016 analysis by Sebastián Apesteguía, Nathan D. Smith, Rubén Juarez Valieri, and Peter J. Makovicky based on the dataset of Carrano et al.

[32] However, Novas et al. subsequently found that megaraptorans lacked most of the key features in the hands of derived coelurosaurs including Guanlong and Deinonychus.

[36][34][35] In 2019, Rauhut and Pol described Asfaltovenator vialidadi, a basal allosauroid displaying a mosaic of primitive and derived features seen within Tetanurae.

Their phylogenetic analysis found traditional Megalosauroidea to represent a basal grade of carnosaurs, paraphyletic with respect to Allosauroidea.

[1] Monolophosaurus Spinosauridae Megalosauridae Xuanhanosaurus Piatnitzkysauridae Asfaltovenator Metriacanthosauridae Allosauridae The relationship between allosauroids and megalosauroids was also supported by a provisional analysis published by Andrea Cau in 2021.

The results of this analysis differ from those of Rauhut and Pol in that Cau finds Megalosauroidea to be monophyletic and the sister-taxon of Allosauroidea within Carnosauria.

[37] Coelurosauria Monolophosaurus Metriacanthosauridae Allosaurus Neovenator Marshosaurus Asfaltovenator Sciurumimus Piatnitzkysauridae Spinosauridae Megalosauridae In 2024, Andrea Cau published a paper which presented an analysis of theropod ontogeny which suggested that several theropods that were traditionally considered coelurosaurs may be juvenile allosauroids or megalosauroids.

This hypothesis has not been universally accepted, and it notably conflicts with Cau's 2021 publication by finding Megalosauroidea as monophyletic and the sister taxon of Avetheropoda, a grouping which includes both carnosaurs (or allosauroids) and coelurosaurs.

Notably, this analysis also treats the abelisauroid genus Kryptops as a chimera and suggests that the postcranial remains of this taxon belong to a carnosaur (possibly Sauroniops).

This healing may indicate that allosauroids had an intermediate metabolic rate, similar to non-avian reptiles, which means they require fewer nutrients in order to survive.

As social animals, allosauroids would share the burden of hunting, allowing injured members of the pack to recover faster.

Along with members of the superfamily Megalosauroidea, allosauroids were the apex predators that occupied the Middle Jurassic to the early Late Cretaceous periods.

This is likely due to regional extinction events, which, along with increased species isolation through the severing of land connections between the continents, differentiated many dinosaurs in the Late Cretaceous.