How Triceratops got its face: An update on the functional evolution of the ceratopsian head

Abstract

Ceratopsian dinosaurs arguably show some of the most extravagant external cranial morphology across all Dinosauria. For over a century, ceratopsian dinosaurs have inspired a multitude of cranial functional studies as more discoveries continued to depict a larger picture of the enormous diversity of these animals. The iconic horns and bony frills in many ceratopsians portray a plethora of shapes, sizes, and arrangements across taxa, and their overall feeding apparatus show the development of unique specializations previously unseen in large herbivores. Here, I give a brief updated review of the many functional studies investigating different aspects of the ceratopsian head. The functional role of the horns and bony frills is explored, with an overview of studies investigating their potential for weaponization or defense in either intraspecific or anti‐predatory combat, among other things. A review of studies pertaining to the ceratopsian feeding apparatus is also presented here, with analyses of studies exploring their beak and snout morphology, dentition and tooth wear, cranial musculature with associated skull anatomy, and feeding biomechanics.

Elevated evolutionary rates of biting biomechanics reveal patterns of extraordinary craniodental adaptations in some herbivorous dinosaurs

“…However, the underlying selection pressures may differ from those of Limusaurus or oviraptorosaurs; ceratopsids retain a relatively long L Bite but have substantial variation in d Bite with many species showing exceptionally short d Bite for their L Sk . That is, ceratopsids exhibit adaptions associated with biting efficiency via modifications to the lever arm of the biting moment for the maximum bite force ( d Bite ) (Nabavizadeh 2018, 2019, 2023). Ceratopsids show additional adaptations for varying mechanical advantages, most notably in the size and position of the coronoid process.…”

Dinosaurs of all ilks bow and pay tribute to Peter Dodson, their intrepid chronicler, in an Anatomical Record Special Issue in his honor

“…Rather, to name just some, they span a glorious gamut: from detailed descriptions of unusual Therapods from New Jersey (really? hadrosaurs, Jimmy Hoffa…who knew Jersey was actually interesting; sorry, JL is a native New Yorker and has little control when commenting on New Jersey; Gallagher, 2023); reports on a new iguanodontian dinosaur from South Africa (Forster et al, 2023); new insights on evolutionary relationships from analyses of the hyolaryngeal apparatus in extant archosaurs (i.e., birds and crocodilians; Yoshida et al, 2023); new reconstructions of the pectoral girdle and forelimb musculature of Megaraptora (Rolando et al, 2023); insights from osteohistology of Dromornis stironi with implications for understanding the histology of Australian mihirung birds (Chinsamy et al, 2023); insightful observations on fracture and disease in a large‐bodied ornithomimosaur with insights into identifying unusual endosteal bone in the fossil record (Chinzorig et al, 2023); a comprehensive assessment of the history and future of the study of morphometrics in the study on non‐avian dinosaurs (Hedrick, 2023); detailed modeling to assess and predict the abundance of large carnivorous dinosaurs of the Upper Jurassic Morrison Formation and the Upper Cretaceous Dinosaur Park formation (by Peter and JL's Yale classmate, the ever‐creative James Farlow; JL is still in awe at all the super‐bright dino dudes that surrounded him at Yale “back in the day”; Farlow et al, 2023); to a number of papers—naturally—on Peter's great love, the ceratopsians, including those by lead Guest Editor Fiorillo (Fiorillo & Tykoski, 2023) and Peter's successor teaching anatomy at Penn, Ali Nabavizadeh (Nabavizadeh, 2023). Even the cover of this Special Issue has been a creative homage to Peter, lovingly created by Anatomical Record Associate Editor (and artist extraordinaire) Adam Hartstone‐Rose (Hartstone‐Rose et al, 2023).…”

Illuminating dinosaurs under the aurora borealis—A commentary on the creation of the Arctic cover for Dinosaurs: New Ideas from Old Bones

“…The nose horn of Pachyrhinosaurus was, as recommended (Hieronymus et al, 2009), reconstructed from the boss of a muskox ( Ovibos ). For the fighting dinosaurs in the background, references were used of fighting birds and lizards (there are some particularly dramatic records of Komodo dragons fighting), but several studies (Farlow & Dodson, 1975; Fiorillo & Tykoski, 2023; Sternberg, 1950) suggest more similarity to the pushing of mammalian megafauna, though whether dinosaurs pushed or crashed heads in this manner is still hotly debated (Farke, 2010; Goodwin & Horner, 2004; Moore et al, 2022; Nabavizadeh, 2023; Snively & Cox, 2008; Snively & Theodor, 2011). Although initial references of multiple taxa were used to imagine this combat, in the end, the only elements that were integrated into the actual reconstructions of the bodies came from lizards (again, mostly varanids) and bird feet (predominantly Struthio ).…”