Limusaurus inextricabilis is a part of the theropod group of dinosaurs which are considered the evolutionary ancestors of the birds. Researchers explained that these dinosaur species shed their “milk teeth” but did not replace them with permanent ones. This clearly explains why birds have beaks and not teeth.
The fossils of these creatures were recovered from Xinjiang in China. The study conducted was based on the analysis of 19 Jurassic ceratosaurian theropod Limusaurus inextricabilis skeletons which were discovered in “death traps”. The skeletons ranged in age from baby to adult which showed a pattern of tooth formation and breakage. The babies had small and sharp teeth while the adults were consistently toothless. James Clark, Professor at the George Washington University, US said, “This discovery is important for two reasons. First, it’s very rare to find a growth series from baby to adult dinosaurs. Second, this unusually dramatic change in anatomy suggests there was a big shift in Limusaurus diet from adolescence to adulthood.” Also, these fossils indicated that baby Limusaurus could have been of carnivores or omnivore genre but during adulthood they eventually turned into herbivores and they would require teeth to chew meat but not plants. The chemical structure in the fossil bones also clearly suggests that a change in diet did take place between the life span of the species. The fossils also could help to show how birds lost their teeth and this study was published in the journal Current Biology.
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