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Triceratops
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A revision of the Late Campanian centrosaurine ceratopsid Styracosaurus from the Western Interior of North America
Abstract The centrosaurine ceratopsid genus Styracosaurus is known from multiple specimens and a multigeneric bone bed in the upper 30 m of the Late Cretaceous Dinosaur Park Formation of southern Alberta, and a single specimen (S. ovatus) from approximately time equivalent sediments of the Two Medicine Formation of Montana. Key cranial elements (nasals and postorbitals) of Styracosaurus appear to undergo similar ontogenetic changes as documented in Centrosaurus. Although all adult-sized centrosaurines except Centrosaurus apertus are known to possess spike-like parietal ornamentation at the P3 position on the parietal, only Styracosaurus has the P4 ornamentation expressed as a well-developed spike. Styracosaurus shows intraspecific variation in the shape of the more anteriorly placed P5–P7 ornamentation that are either the typical unmodified crest-shaped epoccipitals of other centrosaurines or are developed as short spikes. S ovatus from Montana is retained as a valid species based on the autapomorphic convergence of the P3 spikes toward the midline. https://www.researchgate.net/publication/228488692_A_revision_of_the_Late_Campanian_centrosaurine_ceratopsid_Styracosaurus_from_the_Western_Interior_of_North_America Styracosaurus albertensis Lambe 1913, CMN 344, holotype. reconstruction of the skull in anterior view. Missing portions of the skull are reconstructed assuming bilateral symmetry. Portions not preserved on either side or on the midline are drawn in outline. Abbreviations as in Figure 1. Scale bar equals 10 cm.  *This image is copyright of its original author  *This image is copyright of its original author https://www.researchgate.net/figure/Styracosaurus-albertensis-Lambe-1913-CMN-344-holotype-reconstruction-of-the-skull-in_fig1_228488692 
" Coronosaurus by cisiopurple on DeviantArt
Coronosaurus is a genus of centrosaurineceratopsian dinosaurs which lived in the Late Cretaceous, in the middle Campanian stage. Its remains, two bone beds, were discovered by Phillip J. Currie in the Oldman Formation of Alberta, Canada, and its type and only species, Coronosaurus brinkmani, was first described in 2005, as a new species within the genus Centrosaurus. Later studies questioned the presence of a direct relationship, and in 2012 it was named as a separate genus. Coronosaurus means "crowned lizard", coming from "corona", Latin for crown, and "sauros", Greek for lizard; this name refers to the unique, crown-like shape of the horns on the top of its frill. Mass: 2,000 kg (Estimated) "
" Title: The Isle Fan Art: UtahCabob⠀⠀⠀⠀⠀⠀⠀⠀⠀
Artist: @greatestloverart " Tricerato having impaled a raptor (look at the big claw at the hindleg).
" After the centrosaurine fever of 2011, when a mind-boggling number of "new" species were christened based on previously named and/or wrongly assigned horn-faced remains, things slowed to a snails pace in 2012 and we had to wait until November 8th for the first one. But Coronosaurus wasn't it, at least if the order of mention grants priority.
Coronosaurus was announced after the references section, right at the end of the paper that described Xenoceratops, which is an odd place to coin a new critter and came across as something of an afterthought. Nevertheless, it followed the trend of the previous year and was raised by Michael J. Ryan for remains that were previously assigned to a species of Centrosaurus, in this case Centrosaurus brinkmani. But such a low-key announcement is less surprising when you consider that Ryan named Centrosaurus brinkmani himself in 2005! Art: @joschuaknuppe "
" Ceratopsians of the Hell Creek Formation. Artwork by Nobumichi Tamura
Ceratopsia or Ceratopia is a group of herbivorous, beaked dinosaurs that thrived in what are now North America, Europe, and Asia, during the Cretaceous Period, although ancestral forms lived earlier, in the Jurassic. The earliest known ceratopsian, Yinlong downsi, lived between 161.2 and 155.7 million years ago. The Hell Creek Formation is an intensively-studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The formation stretches over portions of Montana, North Dakota, South Dakota, and Wyoming. "
The last triceratop's mating...
" Two Triceratops trying to escape cataclysm. ? by Tuomas Koivurinne " 
It's a well known fact that Triceratops was among the most robust dinosaurs of all. But just how robust, really, was it? The answer may surprise you!
To answer this question, we need to look at available mass estimations and measurements of its limb bones in the literature. Case in point: Going by SpinoInWonderland's GDI, a Triceratops with a 2.5 meter skull weighs at least 10.5 tonnes (possibly 11 due to the reasons I have outlined earlier in this thread), and this would equate to about 14.6 tonnes for AMNH 5040, whose estimated skull length is 275 cm going by GetAwayTrike's skeletal. For limb bone length, given the skull length of 2.5 meters, the femur length is 151.8 cm, which would then equate to a femur length of 167 cm for AMNH 5040. And according to Benson et al. 2014, the humerus to femur ratio in a single Triceratops individual (AMNH 5033) is 78 cm to 103.4 cm, meaning an estimated humerus length of 126 cm for AMNH 5040. What, you may ask, does this have to do with how robust Triceratops is? That shall soon become very apparent. Following Benson, the 103.4 cm femur has a circumference of 49.9 cm, and the 78 cm humerus a circumference of 49.2 cm. These measurements equate to the estimated 167 cm femur and 126 cm humerus of AMNH 5040 having circumferences of 80.6 and 79.5 cm, respectively. And how robust does the resulting animal turn out to be? Putting it mildly, Triceratops ends up as a very good contender for the most proportionally robust dinosaur ever discovered! The mass estimation for AMNH 5033 in the linked file is stated to be 14 tonnes based on limb bone circumference (this, coincidentally, is a very close match for the volumetrically-derived mass of our largest Triceratops specimens that I have outlined above), which would equate to a circumference-based mass of 59 tonnes (!) for a 14.6 tonne animal extrapolating to AMNH 5040's predicted limb bone sizes. What else has limb bones of similar thickness? A 45-75 tonne Notocolossus (humerus circumference 77 cm), a 46 tonne Ruyangosaurus (femur circumference 79.7 cm), and a 55+ tonne Patagotitan (humerus circumference 78.2 cm). And the even more impressive thing is that not only are these animals roughly 3-5 times as big as the ceratopsian, they are titanosaurs, notorious for having very proportionally robust limbs as Greg Paul (2019) noted, so despite all that AMNH 5040 very likely has limb bones of comparable circumference, which does go to show how incredibly robust an animal that Triceratops was. For further comparison, given the disparity between the mass indicated by limb bone strength relative to mass indicated by volume, Triceratops has limb bones proportionally 59.3% more robust than the vast majority of extant terrestrial tetrapods (these animals tend to produce much more accurate results with the equations of Campione and Evans (2012)), which is just as impressive. All things considered, given this extreme robusticity combined with its large size and top-tier offence/defence, it's very easy to see why Triceratops did so well during the Cretaceous and why its fossils are so common. If I was a T. rex, I'd definitely have kept my distance! |
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