#murusraptor

Murusraptor barrosaensis

By Scott Reid

Etymology: Wall Thief

First Described By: Coria & Currie, 2016

Classification: Dinosauromorpha, Dinosauriformes, Dracohors, Dinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Megaraptora

Status: Extinct

Time and Place: Between 89 and 86 million years ago, in the Coniacian age of the Late Cretaceous 

Murusraptor is only known from the Sierra Barrosa Formation of Neuquén, Argentina 

Physical Description: Murusraptor is a Megaraptor, a group of mysterious theropods from the Cretaceous period. These animals spread everywhere except for, notably, North America; but were most common in South America, where they were often found alongside the behemoth Titanosaurs of the region. Medium sized predators, the Megaraptors were unique amongst theropods in a lot of ways - with long arms rather than shortened ones, supporting huge claws for hunting prey; and these arms were potentially able to turn more than those of other dinosaurs. In addition to this, they often seem to make up the Medium-Sized predator Niche in locations that lack animals like Dromaeosaurid raptors. Most Megaraptors are known from fairly poor remains, and as such it’s extremely difficult to determine their exact classification. So that’s fun!

Murusraptor itself was fairly middle of the pack, a little longer than a minivan. It’s possible that it was even longer, as the only known specimen might be a juvenile or subadulit. It had an elongated, narrow snout, and hollow ribs. It also had fairly flattened hips, like other Megaraptors. Unlike other Megaraptors, its ribs were extremely tube like. It also had a weirdly straight base of its tail. Its legs were slender and more like Coelurosaurs than animals more closely related to Allosaurus. In general, it was more slender than other Megaraptors.

Without skin impressions, it is uncertain if Murusraptor had feathers or not; given its smaller size, it seems likely that it did for thermoregulation and, potentially, display. 

By José Carlos Cortés

Diet: As a Megaraptor, Murusraptor would have been carnivorous, mainly feeding on medium sized prey in its environment.

Behavior: Megaraptors are extremely rare, mysterious, and poorly known - even as we research more about them and find more skeletons. This rarity could mean many things - poor environments where they died for fossilization, they were rare in general, or a more solitary lifestyle leading to a lack of multiple skeletons in one place. If it was a solitary predator, it may have been more of an ambush one, as the leg proportions in other Megaraptors do not indicate that they were very adept for rapid movement. Still, despite being a solitary animal, it’s more likely than not that it took care of its young. As in other Megaraptors, it probably manipulated food and other objects in its environment mainly with its hand claws, but it’s difficult to say without fossil evidence from the hands. In general, without more remains it’s hard to tell what Murusraptor would have been like.

This one skeleton does, however, show signs of injury in this individual. Namely, this Murusraptor had bad infections in its brain, and was bitten behind the back of its head which may have lead to the infections, leading to deformities in its head. It also had infected ribs. It’s not known if these illnesses and wounds lead to the Murusraptor dying. This may indicate it was attacked by a larger predator, or by another Murusraptor.

Ecosystem: The Sierra Barrosa was the briefest interval of a series of environments in Neuquén, Argentina, during the late Cretaceous that was dominated by some of the largest land animals of all time - the biggest titanosaurs. This environment was a large plain associated with extensive rivers, and a lot of mud to go along with it. This river plain created the fossil-forming environment that gives such a big clue of this huge, open area. 

By Ripley Cook 

Unfortunately, the Sierra Barrosa is not well studied, and is the most poorly studied formation - environment - of this group of similar environments associated with this river system over the course of about 20 million years. Thus, though Murusraptor is a typical member of these ecosystems - Megaraptors are frequently found in all these environmenets - it’s uncertain what other usual creatures were there along with it. The large titanosaur Mendozasaurus was in this environment, but it was much too big for Murusraptor to eat. The ornithopod Macrogryphosaurus was also present, and this was probably one of the most prevalent sources of food for Murusraptor. No larger theropods are known - which is odd, given the large sauropods - but it would make sense for an Abelisaurid (relatives of animals such as Carnotaurus) to be present as they were present earlier and later than the Sierra Barrosa.

No other living things from this environment - such as plants and smaller animals - are known at this time.

Other: Murusraptor doesn’t help much with the understanding of where Megaraptors fall in the overall theropod family tree. It has traits similar to Carnosaurs and similar to Coelurosaurs - like all Megaraptorans. Multiple phylogenetic analyses were conducted in the original description of this dinosaur, and they found Megaraptorans as both Tyrannosaurs and Carnosaurs. Thus, more research and more specimens are sorely needed.

~ By Meig Dickson

Sources under the cut 

“Mega-candy-raptor” (2018/10/15)

“Murusraptor barrosaensis” ©2016-2017 MicrocosmicEcology. Accessed at their deviantArt site here

[Megaraptors aren’t “raptors”, that is to say dromeosaurs. Unfortunately, we’re not sure what they are. Their nearest relatives may be tyrannosauroids, or they may be nested within Carnosauria with allosaurs and their ilk. Part of the reason this is a problem is because fossils from this group are rare and fragmentary. I used the lack of fossils to inspire their flavor-text--a forest dwelling animal living alone or in pairs would be less likely to fossilize than one in open environments in large groups.

Also, for the Jurassic World fans out there, a megaraptor would be a pretty good chassis to build some Indominus stats around. Add more hit dice, size up to Gargantuan with the ability modifiers to match, and add a few more “cinematic” abilities]

Megaraptor CR 5 N Animal This sleek biped has a long, low skull and muscular arms. Its hands each bear an oversized, wickedly curved claw.

Megaraptors are forest predators that dispatch prey with their powerful arms. Unlike many theropod dinosaurs, which have small limbs and huge heads, the arms of a megaraptor are muscular graspers that dig their oversized claws into the flesh of their victims. Megaraptors are capable of tackling prey larger than themselves, but usually deal with smaller, safer fare.

Megaraptors, unusually for dinosaurs, are monogamous creatures. Males and females are almost identical in size and appearance, and the pair of them maintains a sizable hunting territory. Rival pairs, or lone individuals, are scared away with regular roaring displays—the booming call of a megaraptor can be heard for miles. The parents raise their chicks until they are of nearly adult size, and then the chicks disperse to find their own territories and mates.

Megaraptors grow to about 20 feet long and weigh 2000 pounds.

Megaraptor as Animal Companions

Starting Statistics: Size Medium; Speed 40 ft..; AC +1 natural armor; Attack bite (1d4), 2 claws (1d4); Ability Scores Str 11, Dex 23, Con 10, Int 2, Wis 15, Cha 10; Special Qualities low-light vision, scent, sentinel jaws

7th-Level Advancement: Size Large AC +3 natural armor; Attack bite (1d6), 2 claws (1d6); Ability Scores Str +8, Dex -2, Con +4; Special Qualities grab, impale

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