A scientist works to unearth some of the bones of Nigersaurus taqueti in the African country of Niger in this undated photo.
The sauropod's downward-facing head and hundreds of teeth made it a fern-mowing machine, says a new study in the journal PLoS One, led by University of Chicago paleontologist Paul Sereno.
The first bones of Nigersaurus were found in the 1950s by French paleontologists. In a 1997 expedition 80 percent of its skeleton was recovered, and in 1999, team leader Sereno gave the dinosaur its name.
Nigersaurus lived in what is now the southern Sahara, in a habitat that also supported the enormous crocodilian known as SuperCroc.