Deltadromeus agilis

[Infinity Blade]

Deltadromeus agillis


Known remains of D. agilis.

Temporal range: Late Cretaceous (Cenomanian; ~99.7-94.3Ma[1])

Scientific classification:

Life
Domain: Eukaryota
(unranked): Unikonta
(unranked): Opisthokonta
(unranked): Holozoa
(unranked): Filozoa
Kingdom: Animalia
Subkingdom: Eumetazoa
(unranked): Bilateria
Clade: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Clade: Olfactores
Clade: Craniata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Clade: Eugnathostomata
Clade: Teleostomi
Superclass: Tetrapoda
Clade: Reptiliomorpha
Clade: Amniota
Class: Reptilia or Clade: Sauropsida
Clade: Eureptilia
Clade: Romeriida
Clade: Diapsida
Clade: Neodiapsida
Clade: Archelosauria
Clade: Archosauromorpha
Clade: Archosauriformes
Clade: Crurotarsi
Clade: Archosauria
Clade: Avemetatarsalia
Clade: Ornithodira
Clade: Dinosauromorpha
Clade: Dinosauriformes
Clade: Dinosauria
Order: Saurischia
Clade: Eusaurischia
Suborder: Theropoda
Clade: Neotheropoda
Clade: Averostra
Clade: †Ceratosauria
Genus: †Deltadromeus
Species: †D. agilis

Deltadromeus agilis (“agile delta runner”) is an extinct species of ceratosaurian theropod dinosaur that lived in Morocco (and perhaps Egypt[1][2]) in the Kem Kem Beds[3] around 99.7-94.3 million years ago[1].

Taxonomy:
Deltadromeus was originally described as a coelurosaur by Sereno et al. (1996)[1]. However, it is now considered to have been a ceratosaur[2][4].

Description:
Deltadromeus was around 8 meters long and around the weight of a rhinoceros. Only postcranial remains have been recovered, rendering any skull restorations speculative (teeth in rock shops are also often attributed to the genus, but there is no way to tell if they actually belong to the animal).[2]


Reconstructed skeleton of Deltadromeus with a speculative skull.

It also had an expanded, plate-shaped coracoid and proximal scapula broader than those of other theropods exhibiting the same appearance. Judging from the known remains of the humerus, radius, and ulna, the forelimbs were not reduced.[3]

Cursoriality:
Deltadromeus agilis was named such because Sereno et al. (1996) believed it to have been cursorial based upon its hindlimb proportions[3][5]. A 2016 study on the cursorial limb proportions of carnivorous theropods included Deltadromeus in its analysis. Here, lower leg length was linked to cursorial potential. The femur length of Deltadromeus (741mm) was plugged into the study’s equation for predicted lower leg length, resulting in an expected length of 1,055mm. However, Deltadromeus actually had a lower leg length of 1,134mm, ~7.5% longer than expected for a theropod of its size; this gives Deltadromeus a cursorial limb proportion score (CLP; the study’s means of determining cursorial ability) of +7.5. Hence, Deltadromeus was indeed a cursorial animal as inferenced by Sereno et al.[5]

References:

[1] fossilworks.org/bridge.pl?a=taxonInfo&taxon_no=65366
[2] Genus List for Holtz (2008) Dinosaurs
[3] Predatory Dinosaurs from the Sahara and Late Cretaceous Faunal Differentiation (Sereno et al., 1996).
[4] New abelisaurid remains from the Anacleto Formation (Upper Cretaceous), Patagonia, Argentina (Gianechini et al., 2015).
[5] An approach to scoring cursorial limb proportions in carnivorous dinosaurs and an attempt to account for allometry (Persons & Currie, 2016).

[Cross]

Deltadromeus agilis was recovered as a basal noasaurid abelisauroid by Sereno et al. (2004). 


 
D. agilis appears in the data matrix with the code "??

?01????1?1011111??0001????0?1?1011??111?11??000??001111

1". 



--Literature cited 


Sereno, P. C., Wilson, J. A., & Conrad, J. L. (2004). New dinosaurs link southern landmasses in the Mid–Cretaceous. Proceedings of the Royal Society of London B: Biological Sciences, 271(1546), 1325-1330.