Oddly enough, paleontologists can often piece together a more complete picture of tiny dinosaurs and reptiles compared to their hundred-ton, earthquake-causing cousins. This is because small prehistoric creatures tend to fossilize all in one piece (and all in one place), while the remains of big, lumbering sauropods may only amount to a few stray femurs and collarbones. Here’s a list of the five smallest dinosaurs (and avian and aquatic reptiles) that ever lived, according to the state of current research.
1. Smallest Carnivore: Microraptor
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With its feathers and primitive wings (one set on its forearms and one set on its hind legs), Microraptor might easily have been mistaken for a bizarrely mutated bird. It was, however, a genuine, carnivorous dinosaur, albeit one that only measured about two feet from head to tail and weighed a few pounds. It’s believed that Microraptor subsisted on a diet of insects.
2. Smallest Herbivore: Microceratops
Joe Tucciarone & Jeff Poling
All the truly tiny dinosaurs appear to have lived in China: this smallest of all ceratopsian ("horn-faced") dinos was only about a foot and a half high and weighed all of four pounds. Unlike its much larger, quadrupedal cousins--such as Triceratops and Pentaceratops--Microceratops scooted around quickly on two feet, which probably helped it avoid getting stomped on by bigger dinosaurs.
3. Smallest Pterosaur: Nemicolopterus
Chuang Zhao
It seems that the remains of new pterosaurs (flying reptiles) are being dug up in China every week. In February of 2008, paleontologists discovered the fossil of this smallest pterosaur yet, which had a wingspan of only 10 inches. As befits its wee size, it's believed that Nemicolopterus hopped across the branches of conifers and gingko trees, feeding on insects.
4. Smallest Aquatic Reptile: Lariosaurus
Arthur Weasley
Pound for pound, this sea-going reptile wasn't nearly as tiny as Microraptor or Microceratops, but it's the smallest example of its type yet found. Lariosaurus was about two feet long from head to tail and weighed a little over 20 pounds; perhaps not surprisingly, it went extinct at the end of the Triassic era, when it was supplanted by larger, more agile plesiosaurs and pliosaurs.
5. Smallest Living Dinosaur: Hummingbird
Wikipedia Commons
From the perspective of some evolutionary biologists, dinosaurs never went extinct: they simply evolved into birds. Based on this reasoning (which not all paleontologists accept), the smallest dinosaur that ever lived is the modern hummingbird, various species of which weigh as little as one-tenth of an ounce!
