Dromaeosaurinae

Dromaeosaurinae is a subfamily of the theropod group Dromaeosauridae. The earliest dromaeosaurine is ''Utahraptor'', dating back to the Early Cretaceous period in North America, however, some isolated teeth seems to represent an indeterminate species of dromaeosaurine, coming from the Late Jurassic period in Africa. If true, this will push their range to the Jurassic period, instead of the Cretaceous, as in most dromaeosaurs.

Most dromaeosaurs are small carnivores, however, dromaeosaurines are represented by some of the largest species (''Achillobator'', ''Dakotaraptor'', ''Utahraptor''). So far, ''Dakotaraptor'' is the only dromaeosaurine with evidence of quill knobs, indicating a plumage; based on this, other members likely had them.

Paleobiogeography

Most dromaeosaurines lived in what is now Asia, North America and possibly Denmark during the Cretaceous period, from the Berriasian to the Maastrichtian stages. However, isolated teeth that may belong to African dromaeosaurines have also been discovered in Ethiopia. These teeth date to the Tithonian stage, of the Late Jurassic period.

Description

Most North American and Asian dromaeosaurines from the Late Cretaceous were generally medium to large-sized animals, with an average length between ; i. e., '' Dromaeosaurus'' and '' Yurgovuchia''. However, among the dromaeosaurines were the largest dromaeosaurs ever, with the feathered ''Dakotaraptor'' measuring long, '' Achillobator'' , and ''Utahraptor'' up to .

Dromaeosaurines were a group of eudromaeosaurs that can be recognised in having stouter, box-shaped skulls, as opposed to the other subfamilies, which generally have narrower snouts, also, dromaeosaurines are generally more heavily built than the other members of their family, with thick, heavy-set legs, which were designed more for strength, rather than for speed. They differ from velociraptorines, in having a low DSDI ratio; i. e., their teeth have equal-sized serrations, on both the posterior and on the anterior edges. By contrast, velociraptorines often have larger serrations on the posterior side of the tooth, than the anterior, or no serrations on the anterior side at all.Genus List for Holtz 2012
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According to Turner et al. 2012, technical diagnoses for dromaeosaurines can be established based on the following traits: fully serrated teeth; vertically oriented pubis; pubic boot (or end) projecting anteriorly and posteriorly; the jugal process of the maxilla, in a ventral view to the external antorbital fenestra, is dorsoventrally wide.

Classification

The Dromaeosaurinae was first erected in 1922 by Matthew and Brown as a part of the "Deinodontidae" (now named Tyrannosauridae). It is defined as a monophyletic group including '' Dromaeosaurus'' and all the other dromaeosaurs closer to it than to ''Velociraptor'', ''Microraptor'', ''Passer'' and '' Unenlagia''.

Cladogram (2012):

The exact consensus for the Dromaeosaurinae phylogeny is still uncertain, since most performed phylogenetic analyses have radically different results with some taxa being recovered on different clades or excluded. According to the phylogenetic analysis performed by Senter et al. 2012, '' Yurgovuchia'' represents an advanced dromaeosaurine, closely related to ''Achillobator'', ''Dromaeosaurus'' and ''Utahraptor''.

During the description of Dakotaraptor in 2015, it was proposed a new cladistic analysis using data from the Theropod Working Group; below are the results for this analysys:

However, in the most recent analysis conducted by Currie and Evans in 2019, the most representative members of the Dromaeosaurinae were recovered as velociraptorines, such as ''Achillobator'' and ''Utahraptor''.

See also

* Timeline of dromaeosaurid research
* Dromaeosauridae
* Eudromaeosauria

References

External links

Dromaeosaurinae
in the Paleobiology Database

{{Taxonbar, from=Q909956

Eudromaeosaurs
Fossil taxa described in 1922