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Description

Theropod dinosaurs had diversified into a variety of forms by the Late Jurassic. North American theropods in the Morrison was dominated predominantly by carnosaurs, but among the carnosaurian overlords were the Ceratosaurs, a group that was beginning to arise as predators in the Jurassic. The largest being Ceratosaurus itself.

History:

In 1883, a farmer from Colorado named Marshall Parker Felch unearthed the remains of an articulated specimen of a theropod dinosaur. Having unearthed bones of dinosaurs before, he sent them to Yale where they were examined by Othniel Charles Marsh.
The specimen was in great shape, including a complete skull, ribcage, and tail, missing parts of the limbs, including parts of the fingers, forelimbs and feet. The most prominent feature Marsh noted was the prominent nasal horn atop the skull. Thus, he dubbed the specimen Ceratosaurus nasicornis. The generic named derived from the Greek “keras meaning 'horn’ and sauros meaning ‘lizard’”. The species name derived from Latin “nasus meaning ‘nasal’ and cornu meaning ‘horn’”. Thus, Horned Lizard with Nasal Horn.

Two new species?:

In 2000, two other species were described and attributed to Ceratosaurus. C. dentisulcatus and C. magnicornis described by Samuel Paul Welles and James Madsen. The primary differences being horn structure and size, with the aforementioned species being smaller. However, in 2003, a re-examination of the bones indicated that these dinosaurs were not fully grown. A research team led by paleontologist Oliver Rauhut found that the differences between the type species C. nasicornis were due to ontogenetic variation. Thus, C. dentisulcatus and C. magnicornis are just juvenile or subadult individuals of the type species.

Classification:

When it was first unearthed, the classification of this dinosaur was a puzzle. Marsh’s rival Edward Drinker Cope assigned it to Megalosaurus and its kin and created the (now invalid) synonym “Megalosaurus nasicornis”. This was when paleontologists had no idea about the broader classification of dinosaurs and if they couldn’t figure out a placement, they just lumped it into Megalosaurus since it was the first theropod found and a wastebasket taxon.

German paleontologist Friedrich von Huene however, lumped in Proceratosaurus as a member of the ceratosauria, and placed both of them as part of the broader clade of coelurosauria. This was a position that was accepted well into the 1960s and 70s.

In the 1980s however, this view was challenged and ultimately rejected when a new family of theropod dinosaurs known as the abelisaurs. In a cladistical analysis undertaken in 1985 by Argentinian Paleontologist José Bonaparte found that this dinosaur and the clade ceratosauria was in fact basal to the abelisaurid family.
Furthermore, it was found that Proceratosaurus’ name was actually not warranted as in 2004, a cladistic analysis of Proceratosaurus found it was a true coelurosaur and not even closely related to Ceratosaurus itself.

Thus, this dinosaur and its kin would eventually give rise to dinosaurs that would dominate southern hemisphere in the Cretaceous.

Description:

Despite being smaller than its contemporary counterparts Allosaurus and Torvosaurus, Ceratosaurus was relatively robust in build compared to its contemporaries. The skull bore the iconic nasal horn as well as smaller, circular crests above its eyes. The horn on the skull was likely just the bony core and was probably enveloped in a keratinous extension.

Found in association with skeletons of Ceratosaurus are osteoderms. Bony extensions of scales found on the back of the dinosaur.
This is correlated with its later descendants, the abelisaurs with animals like Carnotaurus also possessing these. It’s highly likely that these dinosaurs did not possess feathers and were completely scaly as even more derived genera have no evidence of them. However, without a body-wide dinosaur mummy of a ceratosaur or abelisaur, one cannot be sure of the body covering that these dinosaurs possessed.

Its forearms while reduced in size compared to carnosaurs, they were still decently muscled and likely still functional. So, unlike its descendants, the Abelisaurs which had arms that were definitely vestigial, Ceratosaurus still had arms that could have been used to grapple with prey.

The skull was more heavily built compared to other dinosaurs at the time and had proportionally long maxillary teeth. Also, the first eight pairs of teeth were more robust compared to the other teeth. While no figures on bite force have been published, it’s possible that it had a stronger bite compared to contemporary carnosaurs.

Nasal Horn Function:

Originally, Marsh proposed that the prominent horn on the nares was used for combat between rival animals or bringing down prey. The horn being used to cut through flesh and to headbutt its quarry when fighting or taking down prey. Recent theories however render this view outdated as it was probably a fragile structure and probably not suitable for headbutting or a weapon.

More likely it functioned as a display structure used to intimidate rival males or to attract mates. As one can see examples of display structures in animals like ground hornbills of today.

Habitat:

The environment Ceratosaurus lived in, the Morrison Formation some 160-146,000,000 years ago was environment that resembled the savannah of Africa. However, there were no grasslands, there were vast fern prairies interspersed with conifer and sequoia forests, as well as floodplains in the region as well. The Morrison also had a seasonal climate shift being similar to Africa as well, with scorching dry seasons and lush rainy seasons.

Multiple species of Sauropods from Brontosaurus to Brachiosaurus lived alongside it. Smaller ornithopods like Dryosaurus and Camptosaurus have also been found as well. The iconic Stegosaurus has been found in this region as well. Competition for this animal included carnosaurian dinosaurs like Allosaurus, Torvosaurus and Saurophaganax.

Prey and Feeding Habits:

While robust, it was not as large as its carnosaur counterparts. Paleontologists have theorized a variety of feeding habits for this dinosaur. In the early 2000s, some paleontologists theorized Ceratosaurus fed primarily on fish. Dr.Robert Bakker led this theory given that the fossils of this dinosaur have been found in association with fish. However, this was later refuted as fossils found alongside fish are common given that the region was a floodplain environment.

Today, many paleontologists believe that this animal was a typical and generalized carnivorous predator. In a form of niche partitioning, Ceratosaurus was likely preying upon smaller animals like Dryosaurus, Nanosaurus by utilizing ambush tactics. Whereas large carnosaurs were hunting larger game like juvenile sauropods and Stegosaurs. However, they also could have scavenged on both Sauropod carcasses given the dry season could have punished the giant sauropods during periods of extreme temperatures.

Extinction:

The extinction of this dinosaur is largely believed to have been due to climate change. Dying out approximately 146,000,000 years ago. Despite the fact that they died out, their dynasty would live on as their cousins, the abelisaurs would dominate the southern hemisphere up until the extinction of dinosaurs.

However, Ceratosaurus remains both a unique springboard for abelisaurs as well as adding a unique representative of predatory dinosaurs in the Morrison Formation.

___________________________________________________________________________________________

Decided to redo my old Ceratosaurus profile by expanding the information as well as add a new dynamic pose for the dinosaur.

It’s easily one of my favorite dinosaurs from the Morrison so I thought I should do it justice in a more fitting pose. In this case, a male Ceratosaurus about to capture a Dryosaurus in his maw.

It was in PMP and was basically a side character but, I liked the scenes it was in.

Ceratosaurus by Tyranachu skin modified by me:

Ceratosaurus (Tyranachu) | ZT2 Download Library Wiki | Fandom

Dryosaurus by Ulquiorra, skin modified by me:

Dryosaurus (Ulquiorra) | ZT2 Download Library Wiki | Fandom

From Past Meets Present:

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

UPDATED: 8/27: Made Ceratosaurus more apparent and edited Dryosaurus.

Description

Theropod dinosaurs had diversified into a variety of forms by the Late Jurassic. North American theropods in the Morrison was dominated predominantly by carnosaurs, but among the carnosaurian overlords were the Ceratosaurs, a group that was beginning to arise as predators in the Jurassic. The largest being Ceratosaurus itself.

History:

In 1883, a farmer from Colorado named Marshall Parker Felch unearthed the remains of an articulated specimen of a theropod dinosaur. Having unearthed bones of dinosaurs before, he sent them to Yale where they were examined by Othniel Charles Marsh.
The specimen was in great shape, including a complete skull, ribcage, and tail, missing parts of the limbs, including parts of the fingers, forelimbs and feet. The most prominent feature Marsh noted was the prominent nasal horn atop the skull. Thus, he dubbed the specimen Ceratosaurus nasicornis. The generic named derived from the Greek “keras meaning 'horn’ and sauros meaning ‘lizard’”. The species name derived from Latin “nasus meaning ‘nasal’ and cornu meaning ‘horn’”. Thus, Horned Lizard with Nasal Horn.

Two new species?:

In 2000, two other species were described and attributed to Ceratosaurus. C. dentisulcatus and C. magnicornis described by Samuel Paul Welles and James Madsen. The primary differences being horn structure and size, with the aforementioned species being smaller. However, in 2003, a re-examination of the bones indicated that these dinosaurs were not fully grown. A research team led by paleontologist Oliver Rauhut found that the differences between the type species C. nasicornis were due to ontogenetic variation. Thus, C. dentisulcatus and C. magnicornis are just juvenile or subadult individuals of the type species.

Classification:

When it was first unearthed, the classification of this dinosaur was a puzzle. Marsh’s rival Edward Drinker Cope assigned it to Megalosaurus and its kin and created the (now invalid) synonym “Megalosaurus nasicornis”. This was when paleontologists had no idea about the broader classification of dinosaurs and if they couldn’t figure out a placement, they just lumped it into Megalosaurus since it was the first theropod found and a wastebasket taxon.

German paleontologist Friedrich von Huene however, lumped in Proceratosaurus as a member of the ceratosauria, and placed both of them as part of the broader clade of coelurosauria. This was a position that was accepted well into the 1960s and 70s.

In the 1980s however, this view was challenged and ultimately rejected when a new family of theropod dinosaurs known as the abelisaurs. In a cladistical analysis undertaken in 1985 by Argentinian Paleontologist José Bonaparte found that this dinosaur and the clade ceratosauria was in fact basal to the abelisaurid family.
Furthermore, it was found that Proceratosaurus’ name was actually not warranted as in 2004, a cladistic analysis of Proceratosaurus found it was a true coelurosaur and not even closely related to Ceratosaurus itself.

Thus, this dinosaur and its kin would eventually give rise to dinosaurs that would dominate southern hemisphere in the Cretaceous.

Description:

Despite being smaller than its contemporary counterparts Allosaurus and Torvosaurus, Ceratosaurus was relatively robust in build compared to its contemporaries. The skull bore the iconic nasal horn as well as smaller, circular crests above its eyes. The horn on the skull was likely just the bony core and was probably enveloped in a keratinous extension.

Found in association with skeletons of Ceratosaurus are osteoderms. Bony extensions of scales found on the back of the dinosaur.
This is correlated with its later descendants, the abelisaurs with animals like Carnotaurus also possessing these. It’s highly likely that these dinosaurs did not possess feathers and were completely scaly as even more derived genera have no evidence of them. However, without a body-wide dinosaur mummy of a ceratosaur or abelisaur, one cannot be sure of the body covering that these dinosaurs possessed.

Its forearms while reduced in size compared to carnosaurs, they were still decently muscled and likely still functional. So, unlike its descendants, the Abelisaurs which had arms that were definitely vestigial, Ceratosaurus still had arms that could have been used to grapple with prey.

The skull was more heavily built compared to other dinosaurs at the time and had proportionally long maxillary teeth. Also, the first eight pairs of teeth were more robust compared to the other teeth. While no figures on bite force have been published, it’s possible that it had a stronger bite compared to contemporary carnosaurs.

Nasal Horn Function:

Originally, Marsh proposed that the prominent horn on the nares was used for combat between rival animals or bringing down prey. The horn being used to cut through flesh and to headbutt its quarry when fighting or taking down prey. Recent theories however render this view outdated as it was probably a fragile structure and probably not suitable for headbutting or a weapon.

More likely it functioned as a display structure used to intimidate rival males or to attract mates. As one can see examples of display structures in animals like ground hornbills of today.

Habitat:

The environment Ceratosaurus lived in, the Morrison Formation some 160-146,000,000 years ago was environment that resembled the savannah of Africa. However, there were no grasslands, there were vast fern prairies interspersed with conifer and sequoia forests, as well as floodplains in the region as well. The Morrison also had a seasonal climate shift being similar to Africa as well, with scorching dry seasons and lush rainy seasons.

Multiple species of Sauropods from Brontosaurus to Brachiosaurus lived alongside it. Smaller ornithopods like Dryosaurus and Camptosaurus have also been found as well. The iconic Stegosaurus has been found in this region as well. Competition for this animal included carnosaurian dinosaurs like Allosaurus, Torvosaurus and Saurophaganax.

Prey and Feeding Habits:

While robust, it was not as large as its carnosaur counterparts. Paleontologists have theorized a variety of feeding habits for this dinosaur. In the early 2000s, some paleontologists theorized Ceratosaurus fed primarily on fish. Dr.Robert Bakker led this theory given that the fossils of this dinosaur have been found in association with fish. However, this was later refuted as fossils found alongside fish are common given that the region was a floodplain environment.

Today, many paleontologists believe that this animal was a typical and generalized carnivorous predator. In a form of niche partitioning, Ceratosaurus was likely preying upon smaller animals like Dryosaurus, Nanosaurus by utilizing ambush tactics. Whereas large carnosaurs were hunting larger game like juvenile sauropods and Stegosaurs. However, they also could have scavenged on both Sauropod carcasses given the dry season could have punished the giant sauropods during periods of extreme temperatures.

Extinction:

The extinction of this dinosaur is largely believed to have been due to climate change. Dying out approximately 146,000,000 years ago. Despite the fact that they died out, their dynasty would live on as their cousins, the abelisaurs would dominate the southern hemisphere up until the extinction of dinosaurs.

However, Ceratosaurus remains both a unique springboard for abelisaurs as well as adding a unique representative of predatory dinosaurs in the Morrison Formation.

___________________________________________________________________________________________

Decided to redo my old Ceratosaurus profile by expanding the information as well as add a new dynamic pose for the dinosaur.

It’s easily one of my favorite dinosaurs from the Morrison so I thought I should do it justice in a more fitting pose. In this case, a male Ceratosaurus about to capture a Dryosaurus in his maw.

It was in PMP and was basically a side character but, I liked the scenes it was in.

Ceratosaurus by Tyranachu skin modified by me:

Ceratosaurus (Tyranachu) | ZT2 Download Library Wiki | Fandom

Dryosaurus by Ulquiorra, skin modified by me:

Dryosaurus (Ulquiorra) | ZT2 Download Library Wiki | Fandom

From Past Meets Present:

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

UPDATED: 8/27: Made Ceratosaurus more apparent and edited Dryosaurus.