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Allosaurus fragilis

The lion of the Jurassic, Allosaurus. An icon of the Jurassic Period, and one of the largest predators that lived around 154,000,000 years ago.

These predators were among the most common carnivores found in the Morrison Formation.
Fossils have been recovered across the American Badlands and Rockies in the Morrison Formation and the coastal formation of Lourinhã Formation in Portugal. These powerful predators ruled the floodplains, forests, and scrubland of their respective ecosystems.

As of 2020, their were 3 valid species of Allosaurus classified. Allosaurus fragilis, Allosaurus jimmadseni, and Allosaurus europaeus. The first two species are found in the Morrison and the lattermost being found in the Lourinhã formation. This species, A.fragilis is the most well-known and type species of the genus.
The biggest differences between the two American species are:
-A.fragilis had a slightly wider skull
-A.jimmadseni had a much thinner snout
-A.jimmadseni was larger in body size.
In terms of A.europeaus, it's only known from a partial skeleton, so not as many details can be extrapolated, however, it is smaller than both American species.
In terms of how the two species functioned in the Morrison, is a mystery. Both of them overlapped in time and in range ~155-145,000,000 years ago. However, with creatures like leopards, lions, and even tigers co-existing in India, its possible these two species did the same. So perhaps niche partitioning is in play between the two species.
But what those roles looked like in the wild is unknown and perhaps will never be fully understood.

As far as larger Allosaurs that lived during this time, like Epanterias or Saurophaganax. Their positions are quite controversial, and only Saurophaganax is believed to be a distinctive genus of Allosaur as of 2021.

Allosaurus is believed to have been the apex predator in its respective region. Preying upon large ornithopods, Stegosaurs and Sauropods.

However, their bite force was a lot weaker than other more iconic predators like Tyrannosaurus. Only around the same as some big cats or hyenas. Despite being far larger. However, its gape was a lot wider than usual. Some paleontologists like Robert Bakker and Emily Rayfield suggested they used their jaws like a hatchet, striking their victims repeatedly till they succumbed to shock and blood loss. The evidence they pointed to was skull was a lot more reinforced than other theropods, and the neck was very heavily muscled, so it'd seem plausible at first glance.

However, while the hatchet-bite is interesting to imagine, the idea has garnered a lot of criticism:

-For one, if the animal didn't hit on the mark, its mandible or cranium, reinforced or not, would shatter or it could split its joint between its cranium or mandible. Especially on a larger animal.
-On a smaller animal, it could perhaps it could pull it off, but it'd also shed a lot of teeth when it hit the bone. Despite the fact that dinosaur teeth regrow throughout their life, shedding teeth repeatedly would not have been a sustainable hunting and/or feeding strategy.

Another study suggests they probably used their neck muscles and reinforced skull to target more fleshy/convex parts of their prey by hooking into areas like the flanks, and then pulling back with its neck muscles and its pure bulk to rip away flesh and muscle.
This also lends credence to a theory in how they took down Sauropod dinosaurs in their region. They basically would not need to take them down, or at least, take down fully grown adults. Allosaurus and perhaps other Carnosaurs were "flesh grazers". They'd use their jaws to get in close to the flanks of a Sauropod and then rip off chunks of flesh. It would be a lot safer and more energy-efficient than expending all your energy in taking down prey alone or in a pack.

Pack behavior in Allosaurus, as well as other theropods, has been a question since the 1970s. While entertaining to watch in documentaries, docudramas, and movies, their is very little evidence suggesting that theropods were pack hunters. Considering modern carnivorous archosaurs are usually more solitary and may occasionally come together in lose associations. It's largely believed to be the same with Allosaurs. However, we will never truly know the extent of Allosaurus behavior considering all paleontology has to work with is just fossilized bones, occasionally skin fragments, trackways, or coprolites.

Allosaurus itself would vanish at the end of the Jurassic. Along with other icons such of this period such as the Diplodocids and Stegosaurs that dominated the landscape.
___________________________________________________________________________________________
This one was relatively easy to modify. I just fleshed in parts of the skull, and modified the snout slightly. I love the Walking With Dinosaurs skin so I chose to leave the base color alone, other than the snout.

Interesting fact, this was the first dinosaur I saw on TV when I was a boy. I saw Prehistoric Planet (A Discovery Kids version of WWD, and REALLY toned down). As an adult, one thing that really irked me on rewatching it was when Ben Stiller (he was the narrator of this version of WWD) said this animal was just 20 feet long, WAT? Even some avg. specimens are around the upper 20s.

The study I referenced:
EG595600.pdf (csic.es)
^^^ It's a good read as well.

UPDATE 5/4/2021: Updated the skull

Based on Franoys restoration of Dino 2560
Allosaurus fragilis skeletal (DINO 2560). by Franoys on DeviantArt

Also, used MithosKuu for the top view
Allosaurus fragilis skull by MithosKuu on DeviantArt
Old Version
i.imgur.com/081taxO.jpg

Original model by DinosaurManZT2 :
WWD Allosaurus / Big Al by DinosaurManZT2 on DeviantArt
Base model that I modified:
Allosaurus (HENDRIX) | ZT2 Download Library Wiki | Fandom

For Past Meets Present:
Past Meets Present (Pt4 is Up) - The ZT2 Round Table

Description
NEW PROFILE

Allosaurus fragilis

The lion of the Jurassic, Allosaurus. An icon of the Jurassic Period, and one of the largest predators that lived around 154,000,000 years ago.

These predators were among the most common carnivores found in the Morrison Formation.
Fossils have been recovered across the American Badlands and Rockies in the Morrison Formation and the coastal formation of Lourinhã Formation in Portugal. These powerful predators ruled the floodplains, forests, and scrubland of their respective ecosystems.

As of 2020, their were 3 valid species of Allosaurus classified. Allosaurus fragilis, Allosaurus jimmadseni, and Allosaurus europaeus. The first two species are found in the Morrison and the lattermost being found in the Lourinhã formation. This species, A.fragilis is the most well-known and type species of the genus.
The biggest differences between the two American species are:
-A.fragilis had a slightly wider skull
-A.jimmadseni had a much thinner snout
-A.jimmadseni was larger in body size.
In terms of A.europeaus, it's only known from a partial skeleton, so not as many details can be extrapolated, however, it is smaller than both American species.
In terms of how the two species functioned in the Morrison, is a mystery. Both of them overlapped in time and in range ~155-145,000,000 years ago. However, with creatures like leopards, lions, and even tigers co-existing in India, its possible these two species did the same. So perhaps niche partitioning is in play between the two species.
But what those roles looked like in the wild is unknown and perhaps will never be fully understood.

As far as larger Allosaurs that lived during this time, like Epanterias or Saurophaganax. Their positions are quite controversial, and only Saurophaganax is believed to be a distinctive genus of Allosaur as of 2021.

Allosaurus is believed to have been the apex predator in its respective region. Preying upon large ornithopods, Stegosaurs and Sauropods.

However, their bite force was a lot weaker than other more iconic predators like Tyrannosaurus. Only around the same as some big cats or hyenas. Despite being far larger. However, its gape was a lot wider than usual. Some paleontologists like Robert Bakker and Emily Rayfield suggested they used their jaws like a hatchet, striking their victims repeatedly till they succumbed to shock and blood loss. The evidence they pointed to was skull was a lot more reinforced than other theropods, and the neck was very heavily muscled, so it'd seem plausible at first glance.

However, while the hatchet-bite is interesting to imagine, the idea has garnered a lot of criticism:

-For one, if the animal didn't hit on the mark, its mandible or cranium, reinforced or not, would shatter or it could split its joint between its cranium or mandible. Especially on a larger animal.
-On a smaller animal, it could perhaps it could pull it off, but it'd also shed a lot of teeth when it hit the bone. Despite the fact that dinosaur teeth regrow throughout their life, shedding teeth repeatedly would not have been a sustainable hunting and/or feeding strategy.

Another study suggests they probably used their neck muscles and reinforced skull to target more fleshy/convex parts of their prey by hooking into areas like the flanks, and then pulling back with its neck muscles and its pure bulk to rip away flesh and muscle.
This also lends credence to a theory in how they took down Sauropod dinosaurs in their region. They basically would not need to take them down, or at least, take down fully grown adults. Allosaurus and perhaps other Carnosaurs were "flesh grazers". They'd use their jaws to get in close to the flanks of a Sauropod and then rip off chunks of flesh. It would be a lot safer and more energy-efficient than expending all your energy in taking down prey alone or in a pack.

Pack behavior in Allosaurus, as well as other theropods, has been a question since the 1970s. While entertaining to watch in documentaries, docudramas, and movies, their is very little evidence suggesting that theropods were pack hunters. Considering modern carnivorous archosaurs are usually more solitary and may occasionally come together in lose associations. It's largely believed to be the same with Allosaurs. However, we will never truly know the extent of Allosaurus behavior considering all paleontology has to work with is just fossilized bones, occasionally skin fragments, trackways, or coprolites.

Allosaurus itself would vanish at the end of the Jurassic. Along with other icons such of this period such as the Diplodocids and Stegosaurs that dominated the landscape.
___________________________________________________________________________________________
This one was relatively easy to modify. I just fleshed in parts of the skull, and modified the snout slightly. I love the Walking With Dinosaurs skin so I chose to leave the base color alone, other than the snout.

Interesting fact, this was the first dinosaur I saw on TV when I was a boy. I saw Prehistoric Planet (A Discovery Kids version of WWD, and REALLY toned down). As an adult, one thing that really irked me on rewatching it was when Ben Stiller (he was the narrator of this version of WWD) said this animal was just 20 feet long, WAT? Even some avg. specimens are around the upper 20s.

The study I referenced:
EG595600.pdf (csic.es)
^^^ It's a good read as well.

UPDATE 5/4/2021: Updated the skull

Based on Franoys restoration of Dino 2560
Allosaurus fragilis skeletal (DINO 2560). by Franoys on DeviantArt

Also, used MithosKuu for the top view
Allosaurus fragilis skull by MithosKuu on DeviantArt
Old Version
i.imgur.com/081taxO.jpg

Original model by DinosaurManZT2 :
WWD Allosaurus / Big Al by DinosaurManZT2 on DeviantArt
Base model that I modified:
Allosaurus (HENDRIX) | ZT2 Download Library Wiki | Fandom

For Past Meets Present:
Past Meets Present (Pt4 is Up) - The ZT2 Round Table