Scientists have discoverd a fossil which they believe to be the world’s smallest dinosaur. Informally dubbed “Ashdown maniraptoran,” the feathered, bird-like dinosaur lived more than 100 million years ago and was just over a foot long. The findings of the recent discovery are published in the most recent issue of the journal Cretaceous Research.
According to the findings, the bone indicates that the dinosaur lived in the Cretaceous period 145 million to 100 million years ago. The bone belongs to a maniraptoran, a group of theropod dinosaurs that scientists speculate eventually evolved into present-day birds. Because the dinosaur has not been formally named yet, researchers refer to it as “Ashdown maniraptoran.” The name reflects the type of dinosaur (maniraptoran) and the location in which it was found (the Pivensey Pit at Ashdown Brickworks, a site located in East Sussex, UK). The dinosaur will be given a formal, scientific name if and when more fossils of its kind are discovered.
Scientists speculate that “Ashdown maniraptoran” was bipedal, meaning it walked on two legs, most likely with its body and tail in a horizontal position. Darren Naish, a paleozoologist who co-authored the research, described the dinosaur as having “a fairly short tail, long neck, long slim hind legs, and feathered clawed forelimbs.”
The neckbone of the dinosaur was discovered in the southern United Kingdom by researchers from the University of Portsmouth. The size of the bone, which is just a quarter inch long, allowed scientists to estimate the full size of the dinosaur. The bone has been identified as a posterior cervical vertebra. Researchers used two methods to estimate the size of the dinosaur. First, scientists built a digital model of the dinosaur’s neck, then fitted the neck into the silhouette of a maniraptoran. The second technique involved using neck-to-body ratios of related dinosaurs to determine the length of the dinosaur. Both of these techniques allowed scientists to estimate that the “Ashdown maniraptoran” measured between 13 and 15.7 inches long.
Despite the tiny size of the dinosaur, researchers have confirmed that it was fully grown when it died. The neckbone that was discovered does not have a neurocentral suture, which is a rough, open line of bone that only closes when a dinosaur is fully grown.
Because the skull of “Ashdown maniraptoran” has yet to be discovered, scientists are not entirely sure about the diet of the dinosaur. Based on similar small dinosaurs, such as oviraptorosaurs and other small maniraptorans, researchers have theorized that the dinosaur was an omnivore that could have eaten small creatures, such as insects, as well as other things like leaves and fruit.
The discovery of the new dinosaur indicates that southern England and other parts of Europe were home to a large population of similar dinosaurs during the Early Cretaceous period. Because there were land bridges connecting Europe to North America during this period, dinosaurs found in Europe share many similarities with dinosaurs found in the United States.
“Ashdown maniraptoran” is not the only tiny dinosaur to have been discovered lately. A dinosaur called Hesperonychus elizabethae was recently discovered in North America. Six inches longer than “Ashdown maniraptoran,” the dinosaur weighed around four pounds and was similar to a velociraptor. A small dinosaur known as Albertonkyus borealis, which had long legs and large claws, is another fairly recent discovery.
If “Ashdown maniraptoran” proves to be the smallest dinosaur in the world, it will take the title of smallest dinosaur previously held by Anchiornis, a bird-like dinosaur that lived in China 160 million to 155 million years ago. Because modern day birds are technically dinosaurs, the world’s smallest dinosaur is the Cuban bee hummingbird, which is 2 inches long and weights just .063 ounces.
Photo Credit: blm.gov/wo/st/en/res/Education_in_BLM/Learning_Landscapes/For_Teachers/science_and_children/paleo/