Paleo Profiles: Nasutoceratops

A reconstructed skull in the Arizona History of Natural History

Recently, the video game Jurassic World: Evolution announced that it would be introducing the not very well known herbivorous dinosaur Nasutoceratops. The Nasutoceratops was a car-sized dinosaur, and is often shadowed, alongside many of its other relatives, by one particular dinosaur which it's related to: Triceratops. Today we'll look at the Nasutoceratops, how it lived, and how it might have behaved.

Discovery and Fossils

Parts of the holotype

Nasutoceratops is a very recent discovery being first found in 2006, and its official description only took until 2013 - quite often fossils can be studied for over a decade before being officially described. A team from the University of Utah found most of a skull and several leg bones in the Kaiparowits Formation, Utah. The amount of well-preserved bones from a specimen, especially the skull, allowed palaeontologists to feel confident enough to name the dinosaur very quickly. As early as 2010 one of the discoverers, Eric Lund, named the dinosaur, but it took until 2013 for the official description to happen. It was named Nasutoceratops titusi meaning 'Large Nosed Horned Face'. A relative of the Triceratops ('Three Horned Face') they thought it was fitting to give it a similar name, especially as the Nasutoceratops had a very distinct nose just like Triceratops.

Biology

The Nasutoceratops belonged to a family of dinosaurs called the Ceratopsidae, or Ceratopsids. These were a family of quadrupedal herbivorous dinosaurs characterised by beaked jaws and elaborate nasal horns. The ceratopsids a further split between two subfamilies - the chasmosaurids and centrosaurids. The chasmosaurids, including Triceratops, were characterised by their large brow horns and elaborate triangular frills; whereas the centrosaurids, which Nasutoceratops belonged to, had elaborate nasal horns, short rectangular frills, but had elaborate spines on the frills. Although Nasutoceratops is classed as a centrosaurid it shares several features of chasmosaurids, such as lacking elaborate spines on the frill and having long brow horns, but the group who described the dinosaur stated that possible convergent evolution was due to this. This is when two or more species, or groups, evolve independently but similarly to suit similar environments - such as how bats and birds are not related but both evolved powered flight for a specific environment. The skull of a Nasutoceratops is a blend of centrosaurid and chasmosaurid skulls as a result. If you looked at a Nasutoceratops head on you would notice how the horns resemble that of cattle and not like Triceratops. Instead of being relatively straight, like that of Triceratops, they curve horizontally so they resemble cattle horns. These horns were very long, the longest among centrosaurids, covering 40% of the 1.5 metre (4.9 ft) long skull - they stretches from the brow to just before the snout. The snout itself is very interesting. Centrosaurids are renowned for their unusual snouts, and Nasutoceratops keeps this precedent by exhibiting a large bony nasal snout, shown below.

A Nasutoceratops skull, from Sampson, Lund, Loewen, Farke and Clayton

Based on the skull size and the preserved front leg bones palaeontologists have estimated that Nasutoceratops was just under 5 metres long. Based on bone texture, the specimen which we have was likely a sub-adult or adult, so it was close to either its full size or close to it. What would a living Nasutoceratops look like? Unfortunately, no skin has been preserved from Nasutoceratops, but based on other species we can make some realistic assumptions. Scott Sampson has suggested that sexual dimorphism may have occurred in ceratopsians. Only a few early ceratopsians, like Protoceratops, show skeletal differences, so Sampson suggested that if there was dimorphism it would be based on the frills. Males would likely have brightly coloured frills to attract mates or scare of rivals - only in a last resort would they use their horns to fight like modern bighorn sheep. Horns could snap, fights could leave deep wounds, and with predators about it was often too risky. There have been debates about whether they would live in herds - traditionally reconstructions have presented ceratopsids as living in herds like modern African buffalo or white rhino. Sampson has suggested that they lived in 'socially complex' herds, while others have suggested that, when herds have been found, that they could be seasonal or herds of young dinosaurs. Modern Indian rhinos form 'bachelor' herds for protection, as an example. Unfortunately, this does not have a simple answer. Finally, Nasutoceratops likely had some feathers. As we have regularly discussed, every year palaeontologists uncover new revolutionary discoveries opening greater insight into the life of the dinosaurs. The discovery of feathers, ranging from hair-like filaments to modern feathers, on dinosaurs is one example. Although no feathers have been found on large ceratopsians, but a primitive ancestor to the ceratopsians have been found with quill-like follicles. A Psittacosaurus found in the Yixian Formation, China was found with these bristles. What they were used for has been debated: display? defence? thermoregulation? It is likely that larger species, like Nasutoceratops, likely had these bristles, which can be seen on a reconstruction of Psittacosaurus below:

Diet

Ceratopsids had leaf-shaped teeth in a beaked mouth, and Nasutoceratops had this design as well. This was perfect for slicing apart tough vegetation close to the ground. Nasutoceratops lived alongside many other species of herbivorous dinosaurs, so an adaptation to low-lying plants would help prevent interspecies competition. The thick beak could slice through tough vegetation which their leaf-shaped teeth could easily slice into smaller pieces. Due to the high fibrous foliage which they ate Nasutoceratops likely had some form of fermentation in its stomach to further break down the vegetation, as modern elephants and rhinos do, to increase nutrient extraction from what they eat. It has been suggested recently that ceratopsids could have scavenged from the kills of carnivores or would eat abandoned eggs in nests for extra protein. This is not unheard of in nature. Deer have regularly been caught eating dead squirrels or scavenging from carcasses, and hippos have even been reported eating other dead hippos! Herbivores have to eat a lot to have enough energy, so scavenging meat would be a quick way to regain lost protein. Meat and eggs would supplement their diet when needed.

When and Where

The Western Interior Seaway

As mentioned earlier Nasutoceratops was discovered in the Kaiparowits Formation in what is now Utah. This is quite unusual for centrosaurids, as most American centrosaurids are found in the North-East US and Canada, meanwhile Nasutoceratops is one of two to be known from outside this region - the other being Diabloceratops. The 'when' answers why this is. Ceratopsians are known from the Late Cretaceous, around 83 to 66 million years ago, and Nasutoceratops lived in a specific time called the Campanian, around 75 million years ago. At this time the United States was split in two by a great inland sea called the Western Interior Seaway. This isolated small pockets of dinosaurs where certain groups were located in only certain locations. Nasutoceratops was descended from a small population of earlier ceratopsians separated from larger populations by the seaway. It also created a warm, wet and humid jungle which Nasutoceratops could be found in. Floodplains and swamps provided ample plant diversity to sustain a wide range of prehistoric life. The Kaiparowits Formation is one of the best fossil sites in the US and has revealed a thriving Cretaceous ecosystem. Two other ceratopsids lived alongside Nasutoceratops, including the elaborately-frilled chasmosaurid Kosmoceratops, and the duckbilled hadrosaurs, including the famous Parasaurolophus. There were threats to Nasutoceratops; the young could fall victim to the raptor Talos and a fully grown adult could potentially be taken down by a tyrannosaurid called Teratophoneous. Although, in the water there was a crocodilian that could eat dinosaurs called Deinosuchus.

The sources I have used are as follows:

-Gregory S. Paul, The Princeton Field Guide to Dinosaurs, Second Edition, (Princeton: Princeton University Press, 2016)

-Eric Lund, Scott Sampson, and Mark Loewen, 'Nasutoceratops titusi (Ornithischia, Ceratopsidae), a basal centrosaurine ceratopsid from the Kaiparowits Formation, southern Utah', Journal of Vertebrate History, 36:2, (2016)

-'Nasutoceratops', Prehistoric-Wildlife.com, [Accessed 31/08/2019]

-Scott Sampson, Eric Lund, Mark Loewen, Andrew Farke, and Katherine Clayton, 'A remarkable short-snouted horned dinosaur from the Late Cretaceous (late Campanian) of southern Laramidia', Proceedings: Biological Sciences, 280:1766, (2013), 1-7

-Peter Dodson, The Horned Dinosaurs: A Natural History, (Princeton: Princeton University Press, 1996/2017) 

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