On Monday, news surfaced of a strange new dromaeosaur from the late Cretaceous of Romania. Its name is Balaur bondoc
and it was around the size of (and most closely related to) the well-known Velociraptor
. This is no ordinary dromaeosaur, though - it has several bizarre anatomical features that set it apart from any raptor yet discovered.
The most notable of these is the presence of double sickle claws
on each foot. The second toe in dromaeosaurids is the one that typically sports the unique large retractable claw that's common to the clade, but in Balaur
the first toe - usually a tiny hallux in other theropods - has been modified through evolution to mimic the appearance and function of the second. This strange feature is no random mutation, either. The paleontologist responsible for its discovery, Zoltán Csiki of the University of Bucharest, makes it clear in his PNAS publication
that this new raptor exhibits a fair number of unusual features that are specific to its powerful toes, feet and legs. These are called "autapomorphies" and, when in association like this, are very unlikely to be single, random mutations, though they may look that way at first glance.
Other odd features of Balaur
include its unusually short, stout skeletal structure and limbs. Its name means "stocky dragon" in Romanian and refers to its unusual heftiness. Also peculiar are its hands, which contain a reduced and completely nonfunctional third finger. The atrophied state of its hands, along with the powerful structure of its legs and feet, indicate that the animal probably hunted primarily with the weapons on the lower half of its body.
For more information, please see the Wikipedia article
as well its accompanying illustration