Haplocheirus (Greek for "simple hand"); pronounced HAP-low-CARE-us
Plains of central Asia
Late Jurassic (160 million years ago)
Size and Weight:
About 10 feet long and 100 pounds
Short arms; large claws on hands; feathers
Paleontologists have long suspected that birds evolved not once, but multiple times from the feathered theropods of the Mesozoic Era (although it seems that only one line of birds survived the K/T Extinction 65 million years ago and evolved into the modern variety). The discovery of Haplocheirus, an early genus in the line of bipedal dinosaurs known as "alvarezsaurs," helps confirm this theory: Haplocheirus predated Archaeopteryx by millions of years, yet it already displayed various bird-like features, such as feathers and clawed hands. Haplocheirus is also important because it sets the alvarezsaur family tree back a whopping 63 million years. Previously, paleontologists had dated these feathered theropods to the middle Cretaceous period, while Haplocheirus lived during the late Jurassic.