A new fossil could help researchers gain insight into herbivore evolution.
Caseid herbivores are the "largest known terrestrial vertebrates of their time," a PLOS news release reported.
These herbivores evolved from small non-herbivore members of the same group. When vertebrates moved to land they changed the entire terrestrial ecosystem. When herbivores started to develop they played a "key role" in these changes.
The Eocasea martini fossil was found in Kansas, and was a member of the early caseids.
In the study "researchers describe and discuss the evolutionary and paleoecological implications of this new taxon," the news release reported.
The earliest recorded caseid was E. martini, which existed during the Late Carboniferous, between 305 and 300 million years ago
The pattern is "mirrored" by three other groups of species "documenting multiple, independent, but temporally staggered, origins of herbivory and a possible increase in body size among early terrestrial tetrapods, leading to patterns consistent with modern terrestrial ecosystems," the news release reported.
The fossil is believed to have been a small carnivore, providing evidence that herbivorous caseids evolved from carnivores.
"The evolution of herbivory was revolutionary to life on land because it meant terrestrial vertebrates could directly access the vast resources provided by terrestrial plants," paleontologist Robert Reisz, Department of Biology, said in the news release. "These herbivores in turn became a major food resource for large land predators."
The researchers documented this evolution from carnivore to herbivore for the first time in history.
"This pattern is mirrored by three other clades, documenting multiple, independent, but temporally staggered origins of herbivory and increase in body size among early terrestrial tetrapods, leading to patterns consistent with modern terrestrial ecosystem," the researchers wrote in the study abstract.
The research was published in the journal PLOS ONE and was conducted by Robert Reisz from University of Toronto and Jörg Fröbisch of the Museum für Naturkunde.
