Meet Linhenykus monodactylus, the dinosaur that gave the world the finger. This parrot-sized theropod isn’t being surly. It just doesn’t have a choice: it’s the first single-digit dinosaur ever discovered.
In this week’s Proceedings of the National Academy of Sciences, Xu Xing and colleagues document their find, which turned up in a fossil-rich part of northern China. Linhenykus is probably about 80 million years old.
Linhenykus monodactylus is a member of the theropod dinosaurs, the group of two-legged carnivores that includes Tyrannosaurus rex and Velociraptor. Most theropods had three fingers on each hand. But Linhenykus belongs to a family known as the alvarezsauroids: small, long-legged dinosaurs that had one big finger alongside two barely functional nub fingers. [National Geographic]
For humans, losing fingers is a serious hindrance. For theropods, though, fingers weren’t particularly useful. So as theropods spread around the world over the years, they began to lose them.
The earliest carnivorous dinosaurs had five fingers, although only four were actually functional. Many later meat-eaters had only three, and evolution left the mighty Tyrannosaurus rex with only two. Now researchers have unearthed the first known dinosaur with only one finger. [ScienceNOW]
If this little nub had any purpose, Xu speculates, it was likely for scratching up termite mounds to expose and eat the termites. But given the adaptations for the consumption of termites that nature has come up with, Linhenykus‘ one little finger seems a little sad.
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Image: Julius Csotonyi