A recently uncovered creature, roughly the size of a football, possessing the ability to chew plant material like a dedicated herbivore, may stand as the earliest known vertebrate to adopt such a diet. Known as Tyrannoroter heberti, this species thrived around 315 million years ago during the late Carboniferous era within a dense, fern-filled swamp located on what is now Cape Breton Island in Nova Scotia. At that time, most four-legged animals, or tetrapods, primarily consumed other animals as they had not yet developed the capability to chew and digest vegetation.
According to a recent study published in Nature Ecology and Evolution, Tyrannoroter represents the earliest tetrapod with the appropriate dental structure for a plant-based diet, signifying a significant shift in understanding the pace of this dietary transition. This creature, classified as a “microsaur,” existed before the emergence of reptiles and mammals and shares similarities with a group of microsaurs known as pantylids.
The skull of Tyrannoroter was discovered among various animal fossils entwined in the roots of a massive, petrified tree stump protruding from a cliffside on Cape Breton Island. The stump was initially found by amateur paleontologist Brian Hebert, and the species name heberti was dedicated to him in recognition of this discovery. Tyrannoroter likely resembled other pantylids like Pantylus, with a compact body structure tailored for digging.
Noteworthy for its unique multiple rows of “Hershey-kiss” shaped teeth, Tyrannoroter exhibited teeth specialized for consuming plant material. These teeth, an early adaptation for consuming shoots and leaves, possessed additional rows or “batteries” that provided the necessary surface area for grinding vegetation. This dental feature predates other known animals with similar teeth, indicating an innovative dietary strategy for its time.
The evolution of herbivores holds critical importance in understanding ecosystems and plant-animal interactions. Tyrannoroter’s potential herbivorous nature suggests an early experimentation with plant-based diets, shedding light on ancient dietary adaptations among vertebrates. Researchers like Robert Reisz emphasize the significance of investigating further to uncover more insights into the herbivory origins of early tetrapods.
