Triceratops, a genus of horned dinosaurs that roamed the Earth millions of years ago, has long fascinated paleontologists and dinosaur enthusiasts alike, largely for its massive skull and iconic three-horned face. Yet, despite its fame, much of the internal anatomy of its skull has remained an enigma. A team of researchers, including scientists from the University of Tokyo, has embarked on a pioneering study utilizing CT scans and comparative anatomy to unravel the mysteries of the Triceratops’ nasal cavity, revealing unexpected complexity that reshapes our understanding of dinosaur physiology.

Unlike most modern reptiles, Triceratops possessed an unusually large nasal cavity whose internal structures have been elusive due to the impossibility of directly observing soft tissues in fossils. By performing high-resolution X-ray computed tomography (CT) scans on fossilized skulls and integrating this data with anatomical knowledge derived from extant reptiles such as birds and crocodilians, the researchers constructed a detailed 3D model of the nasal cavity. This sophisticated approach allowed them to hypothesize the arrangement of nerves, blood vessels, and respiratory structures that once inhabited this enormous snout.

One of the study’s striking breakthroughs is the revelation that Triceratops had unique neural and vascular pathways within their noses. Typically, in reptiles, nerves and blood vessels reach the nostrils via routes associated with the jaw and nose. However, due to the skull morphology of the Triceratops, the usual jaw routes were obstructed, compelling these vital tissues to traverse through the nasal branch alone. This adaptation indicates an evolutionary rewiring that supports the demands of the dinosaur’s disproportionately massive nasal region, a feature that correlates with its iconic head size.

Further investigation into the nasal soft tissues uncovered something groundbreaking: evidence for a respiratory turbinate within the nasal cavity. Respiratory turbinates are delicate, curled bony or cartilaginous structures which amplify the surface area inside the nose to facilitate heat and moisture exchange. While rare among dinosaurs, this trait is present in their closest living relatives, birds, as well as mammals. The presence of such structures in Triceratops suggests an advanced physiological mechanism to regulate internal body temperature and moisture retention.

This discovery challenges the traditional paradigm that most dinosaurs were ectothermic or “cold-blooded.” Although Triceratops was not likely fully warm-blooded, the respiratory turbinate may have provided a means to mitigate the heat generated by its large skull and maintain homeostasis, enhancing its ability to survive in varied climatic conditions. Such complexity points to a nuanced thermal physiology that blurs the boundaries between cold- and warm-bloodedness.

The researchers base their conclusions on detailed analysis of the turbinate’s anatomical marker — a distinctive ridge on the nasal cavity wall. This ridge matches the location of attachment points observed in modern birds, which possess known respiratory turbinates. Despite the scarcity of direct fossil evidence of soft tissues, comparative morphology has enabled the team to infer the likely presence of these structures in horned dinosaurs. This methodological innovation highlights how paleontologists can bridge massive evolutionary gaps using contemporary analogues.

The evolutionary implications of this study are profound. As the last group of dinosaurs to have their cranial soft tissues systematically investigated, horned dinosaurs like Triceratops close a pivotal chapter in dinosaur biology. Researchers have now pieced together a comprehensive hypothesis about the soft-tissue anatomy that once filled their skulls, providing fresh insight into how these animals might have lived, interacted, and adapted to their environments.

Lead researcher Seishiro Tada, who has been studying reptilian cranial evolution since his graduate studies, emphasized the intricate puzzle-like nature of this work. “Piecing together 3D-printed segments of a Triceratops skull allowed me to visualize how nerve and blood vessel pathways adapted to support their massive noses,” he noted. This hands-on, spatial approach to paleontological reconstruction is revolutionizing our ability to interpret fossilized remains beyond bone structure alone.

Looking beyond the nose, the research team plans to expand their investigations to other distinctive cranial features, such as the frills adorning the back of Triceratops skulls. These frills have captivated scientists for decades, yet their functional anatomy remains poorly understood. Exploring the soft tissues associated with these structures could shed light on their role in thermoregulation, communication, or defense.

This research also underscores the value of multidisciplinary collaboration, combining paleontology, anatomy, evolutionary biology, and advanced imaging technology. By bridging these fields, scientists have achieved a level of anatomical resolution previously deemed impossible for extinct taxa, opening avenues for reinterpreting dinosaur biology with a newfound clarity.

The study has been published in The Anatomical Record, providing a detailed methodology and comprehensive illustrations of the reconstructed nasal anatomy. Its implications extend beyond Triceratops to other ceratopsian dinosaurs, refining our broader understanding of how these magnificent creatures functioned in their ecosystems.

Funding from the Japan Society for the Promotion of Science (JSPS), alongside the support of the JSPS Overseas Challenge Program for Young Researchers, facilitated this technologically intensive research. The team’s efforts continue a tradition of pioneering anatomical work emanating from the University of Tokyo, a leading institution in natural sciences.

In conclusion, these findings illuminate not only the anatomy but also the physiology and perhaps the evolutionary trajectories of horned dinosaurs. The integration of modern technology with foundational comparative anatomy offers an unparalleled window into the prehistoric past, casting new light on how the iconic Triceratops and its kin might have navigated their world. As soft tissue reconstructions advance, our perception of dinosaurs evolves beyond static skeletons into dynamic, living creatures adapting in complex ways.

Subject of Research: Animal tissue samples
Article Title: Nasal soft-tissue anatomy of Triceratops and other horned dinosaurs
News Publication Date: 7-Feb-2026
Web References: https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.70150
References: Seishiro Tada, Takanobu Tsuihiji, Hiroki Ishikawa, Noriyuki Wakimizu, Soichiro Kawabe, Kodai Sakane, “Nasal soft-tissue anatomy of Triceratops and other horned dinosaurs”, The Anatomical Record, DOI: 10.1002/ar.70150
Image Credits: ©2026 K. Sakane CC-BY-ND

Keywords: Triceratops, horned dinosaurs, nasal cavity, soft tissue anatomy, respiratory turbinate, CT scan, paleontology, dinosaur physiology, evolutionary biology, cranial anatomy, thermal regulation

Lobe-finned fishes, a lineage that today counts only eight extant species including lungfish and coelacanths, underwent an explosive diversification of jaw morphologies and functions during the Devonian period—approximately 359 to 423 million years ago. This period, often dubbed the “Age of Fishes,” was pivotal in vertebrate history, marked by dynamic evolutionary experimentation. The research team employed high-resolution 3D models derived from CT scans of fossil specimens, meticulously reconstructing the jaw mechanics of 86 fish species spanning Silurian to Devonian periods. Their comprehensive analysis disclosed that lobe-finned fishes evolved jaw structures with markedly higher rates of change and functional innovation than their contemporaries, the ray-finned fishes.

Ray-finned fishes, today encompassing over 33,000 species and representing the most speciose vertebrate group, exhibited considerably slower evolutionary rates in jaw development during this era. This discovery is paradoxical given the vastly greater diversity and ecological dominance of ray-finned fishes in the present day. The coelacanth, a notable lobe-finned fish, famously rediscovered in 1938 after being considered extinct, underscores the group’s enigmatic legacy. Although modern lobe-finned fishes appear evolutionarily stagnant with limited jaw variation, the fossil record reveals an ancient past marked by rapid morphological experimentation and adaptation.

The lead author of the study, postdoctoral researcher Emily Troyer, emphasized the transformative insights afforded by integrating fossil data with cutting-edge imaging techniques. “Without the fossil record, we would have no idea of this inverted role reversal,” Troyer noted. The ability to peer back hundreds of millions of years enabled the researchers to challenge preconceived notions concerning evolutionary dynamics of early vertebrates. It also highlights the critical importance of paleontological data in understanding how major evolutionary innovations unfold through deep time.

Central to their investigation was the concept of mechanical advantage in jaw function—a biomechanical metric describing how effectively a jaw converts muscle force into bite force. By mapping mechanical advantage across species, the team could infer the functional consequences of observed morphological changes. Lobe-finned fishes developed robust, heavily muscled jaws during the early Devonian, an adaptation likely correlated with feeding on hard-shelled prey such as early clams and crustaceans. This suggests that ecological pressures related to diet played a crucial role in driving jaw diversification.

Digital reconstructions allowed detailed quantification of jaw shape, size, and leverage, revealing an adaptive radiation characterized by rapid morphological shifts. Adaptive radiation describes a process where a lineage diversifies rapidly into a range of different forms in response to ecological opportunities or innovations. The lungfish and coelacanth lineages, therefore, represent an ancient instance of this evolutionary principle, manifesting through novel feeding strategies embodied in jaw morphology and mechanics. These evolutionary adaptations were tightly linked with Devonian ecosystems, which presented new niches and resources.

Co-first author Rafael Rivero-Vega contributed significantly to the study by compiling CT scan data for nearly every complete fossil jaw of lobe-finned fishes available in museum collections. His work involved intricate 3D modeling and mapping of jaw characteristics to test hypotheses surrounding evolutionary tempo and mode. Rivero-Vega highlighted how each fish group encountered unique evolutionary pressures, resulting in distinct patterns of jaw diversification and stasis. Some evolved rapidly before stabilizing upon reaching functional ecological niches, while others displayed more gradual morphological changes aligned with terrestrial transitions.

This research frames evolutionary innovation as a variable and context-dependent process, with different vertebrate lineages exploring morphological and functional possibilities at their own pace. The Devonian jaw innovations in lobe-finned fishes predate the rise of tetrapods and the well-known dinosaur clades by hundreds of millions of years, demonstrating how foundational these early adaptations were to vertebrate evolution. Additionally, the study provides a nuanced understanding of how the interplay between form, function, and environment shapes evolutionary pathways.

The implications extend beyond paleontology, informing developmental biology and ecology by illustrating how morphological traits can be influenced by both biomechanical constraints and ecological opportunity. The use of advanced imaging technologies like CT scanning and 3D biomechanical modeling serves as a blueprint for future evolutionary investigations, enabling scientists to derive functional insights from fossilized remains that were previously unattainable. These methodological innovations breathe new life into the study of ancient life, bridging gaps between form and function across geologic epochs.

In sum, the discovery of a shifted evolutionary tempo between lobe-finned and ray-finned fishes during the Devonian challenges conventional narratives about vertebrate history. Rather than a straightforward trajectory toward the modern dominance of ray-finned fishes, the fossil record reveals a complex story of innovation, experimentation, and adaptation. This study not only underscores the richness of this evolutionary tapestry but also invites a reconsideration of how evolutionary potential is expressed unevenly across diverse lineages and time periods.

Subject of Research: Animals
Article Title: Macroevolutionary role reversals in the earliest radiation of bony fishes
News Publication Date: 1-Sep-2025
Web References: http://dx.doi.org/10.1016/j.cub.2025.08.008
Image Credits: E.M. Troyer/University of Michigan
Keywords: Life sciences, Developmental biology, Ecology, Evolutionary biology