For more than 100 million years, a wide variety of dinosaurs have survived on Earth.
However, dinosaurs that could swim or dive are not commonly found in the existing fossil record, and non-avian theropods were mostly terrestrial.
And a recent study published in Communications – Biology reports a new non-avian dinosaur with a streamlined body shape similar to modern diving birds such as penguins and puffins, the first of its kind in theropods.
Scientists studying a sample of fossil remains from Mongolia’s Omnogovi province have identified a new species named Natovenator polydontus, which means “swimmer-hunter with many teeth”.
This is a relatively complete skeleton including skull, spine, one forelimb and the remains of two hindlimbs.
In addition to having a streamlined body (ribs pointing toward the tail) similar to modern diving birds, this dinosaur had a long neck similar to modern waterfowl (e.g., geese).
These features may have reduced its drag when swimming and helped catch prey.
The researchers also analyzed Natovenator’s evolutionary relationship with other theropod dinosaurs, and
They concluded that it was related to Halszkaraptor, another class of non-avian theropod dinosaurs.
And previous studies have suggested that Halszkaraptor may have adapted to a semi-aquatic lifestyle, similar to that of today’s waterfowl.
A common feature of these studies, Natovenator is a semi-aquatic diving predator that provides additional insight into the evolution of theropods.