Tiny dinosaur

Tiny dinosaur:

• US and British researchers said: a rare juvenile skull of a 190 million year old dinosaur may help explain when an important group of plant eaters branched off from carnivorous cousins. The tiny skull belonged to a young Heterodontosaurus.
  


• The scientists said: Its tooth structure sharp canine teeth for biting and tearing and flat grinding teeth suggest the tiny creature was evolving from a meat eater to a plant eater.
  


• "This juvenile skull indicates that these dinosaurs were still in the midst of that transition," said Laura Porro. Porro came across the skull in a drawer in the Iziko South African Museum in Cape Town, South Africa, while researching the eating habits of adults of this type of dinosaur. Porro said paleontologists had thought the canines were sexually dimorphic a trait present only in adults of one gender in a species like antlers in male deer.
  But the presence of long, serrated canines in the juvenile suggest they were common to both genders, Porro said.
  
  "They almost look like little saber toothed tiger teeth." The first dinosaurs appeared about 230 million years ago, and the earliest known ones were meat eaters. There were other plant-eating dinosaurs at the time of Heterodontosaurus. Later ornithischians included the duck billed dinosaurs, horned dinosaurs such as Triceratops and tank-like dinosaurs such as Ankylosaurus.
  
  While adult Heterodontosaurus were turkey-sized creatures that reached just over three feet (1 meter) in length and weighed about 5 pounds (2.5 kg), the juvenile likely weighed less than half a pound (200 grams) and would have been just about a foot and a half long.
  

The find also offers a rare chance to compare a young dinosaur to adults in the species. Porro said the eyes in the juvenile skull are much bigger, and the nose is much shorter.