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Arjan Mann holds a 3D-printed replica of Tyrannoroter\u2019s skull at Chicago\u2019s Field Museum.\u00a0Credit: Field Museum<\/p>\nA chunky, four-legged creature the size of a football has forced a reconsideration of one of evolution\u2019s more practical questions: when did land animals first develop a taste for plants.<\/p>\n
The answer, based on a 307 million year old skull found inside a fossilized tree stump in Nova Scotia, appears to be much earlier than textbooks suggest. The specimen preserves dental equipment unlike anything paleontologists expected to find in such an ancient terrestrial vertebrate.<\/p>\n
What emerges from the bone is not merely a new species, but a revision to the timeline of how ecosystems on land assembled themselves. The creature belonged to a lineage that predates the split between reptiles and mammals, yet its mouth contained tools designed for grinding vegetation.<\/p>\n
Teeth That Ground the First Greens<\/p>\n
Researchers led by Dr. Arjan Mann of the Field Museum in Chicago and Zifang Xiong of the University of Toronto subjected the skull to high resolution micro CT scanning. The images showed rows of robust teeth on both the lower jaw and the palate, or roof of the mouth. When the animal closed its mouth, these surfaces interlocked like puzzle pieces.<\/p>\n
Arjan Mann holds a 3D-printed replica of Tyrannoroter\u2019s skull at Chicago\u2019s Field Museum.\u00a0Credit: Field Museum<\/p>\n
Analysis of tooth wear patterns revealed facets consistent with shearing and grinding motions typical of plant processing. The findings, detailed in a study published February 10 in the journal Nature Ecology & Evolution, identified the species as Tyrannoroter heberti. The complete research paper in Nature Ecology & Evolution<\/a> provides extensive data on the dental morphology and phylogenetic analysis supporting the identification.<\/p>\n The name honors Brian Hebert, the avocational paleontologist who found the fossil, while referencing the animal\u2019s probable use of its snout for digging. The creature measured roughly one foot in length with a stocky build resembling modern shingleback skinks. It lived during the Late Carboniferous Period, approximately 307 million years ago, in what is now Cape Breton Island.<\/p>\n The specimen was recovered from cliffs exposed to extreme tidal shifts, conditions that Mann described as requiring paleontologists to race against incoming tides. A report from the Field Museum via EurekAlert<\/a> details the challenging fieldwork conditions and the role of Brian Hebert in spotting the small skull within a fossilized tree stump.<\/p>\n When Vertebrates First Learned to Graze<\/p>\n The discovery pushes back the established timeline for herbivory among land vertebrates. Previous fossil evidence suggested that specialized plant eating emerged primarily among amniotes, the group that includes reptiles, birds, and mammals. Tyrannoroter belongs to a broader category called stem amniotes, animals closely related to the ancestors of all modern land vertebrates but predating the evolutionary split between reptile and mammal lineages.<\/p>\n \u201cThis shows that experimentation with herbivory goes all the way back to the earliest terrestrial tetrapods,\u201d Mann said in materials accompanying the publication. The researchers note that Tyrannoroter likely maintained an omnivorous diet that included insects.<\/p>\n Hans Sues, senior research geologist at the Smithsonian National Museum of Natural History and study co author, has previously observed that nearly all modern herbivores consume some animal protein. The mechanical demands of processing hard insect exoskeletons may have preadapted the dentition for handling tough plant material. As CNN\u2019s coverage of the discovery<\/a> notes, this dietary shift would have required more than specialized teeth, likely including larger guts and robust microbial communities to break down fibrous plants.<\/p>\n The study also examined historical fossils of related pantylid species, finding evidence that similar dental adaptations existed as far back as 318 million years ago. This suggests herbivory became established among these groups relatively quickly after vertebrates became fully terrestrial.<\/p>\n A Menu That Rewrote Evolution<\/p>\n![\"A](\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2026\/02\/a-reconstruction-of-tyrannoroter-heberti-eating-a-fern-illustration-by-hannah-fredd.jpeg\")
A reconstruction of Tyrannoroter heberti, eating a fern. Illustration by Hannah Fredd<\/p>\n![\"Arjan](\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2026\/02\/1771290616_900_img-0269-20260205212138653.jpg\")
Tyrannoroter\u2019s skull, held by Arjan Mann. Photo by Arjan Mann<\/p>\n
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An Australian shingleback skink resembles what researchers believe the Tyrannoroter looked like.\u00a0Credit: G Lacz\/imageBROKER\/Shutterstock<\/p>\n