Thanks to seeds and toothless beaks, today's birds' ancient ancestors survived periods of mass extinction while their land-based counterparts went extinct. A recent research has found that munching on seeds helped saved some of these feathered theropod dinosaurs.

When the massive asteroid hit Earth approximately 66 million years ago, the sudden climate change also made it difficult for most plants to grow. This means the survivors had to fight for food sources.

Seeds were compact and stronger than their full-grown counterparts and the ones stuck in the ground became resilient food sources for many bird-like dinosaurs that survived the mass extinction.

A research team investigated the collective data on 3,104 fossilized teeth from the maniraptoran dinosaurs, which were the smaller, carnivorous theropod dinosaurs that lived in the Cretaceous period.

These maniraptoran dinosaurs had a mouth full of teeth, which supported their carnivorous diets and the modern-day birds were said to have stemmed from the maniraptoran dinosaurs.

The researchers were looking for diversity patterns in the fossilized teeth, which covered approximately 18 million years up to the Cretaceous period's end.

The team reasoned that if the teeth diversity variation decreased gradually, it suggests the parallel decline of the ecosystem as well as a long-term loss of the species.

Otherwise, a steady variation would suggest that the species were killed off abruptly in an ecosystem that was rich and stable.

"The maniraptoran dinosaurs maintained a very steady level of variation through the last 18 million years of the Cretaceous. They abruptly became extinct just at the boundary," said paleontologist Derek Larson, the study's first author and a University of Toronto doctoral candidate.

The researchers theorized that the modern-day birds' last common ancestor was a seed eater with a toothless beak. This suggested that the several lineages survived and gave rise to modern birds by eating seeds following the asteroid hit.

The team found that there were many toothed theropod dinosaurs up until the Cretaceous period's end, but these survivors died abruptly. Larson added that some beaked bird groups were able to live out the devastating effects of the asteroid hit because they were able to munch on seeds for survival.

The research was published in the journal Current Biology on April 21 and funded by the Dinosaur Research Institute, the Natural Sciences and Engineering Research Council of Canada and the Doris O. and Samuel P. Welles Research Fund.

Photo: Oregon State University | Flickr

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