A close look at the fossils of a group of bipedal dinosaurs known as oviraptors suggests that many species in the lineage shook their muscular, feather-adorned tails to gain attention during courtship. The key evidence, the scientists say, is the structure of the relatively stubby tail—muscular and flexible at its base but rigid at its tip, where the last half-dozen or so vertebrae are either fused together into a bladelike structure or so tightly arranged that they're inflexible. There's no sign that the dinos' muscular tails were adorned with structures that would have rendered them a weapon. However, some fossils of early members of the group that lived about 150 million years ago have included large feathers that were either attached to the last few tail vertebrae or preserved in their vicinity, suggesting the presence of a fan-shaped display at the end of the appendage. A new study of later species in the same lineage reveals that these dinosaurs had the same arrangement of tail vertebrae and the muscles used to control their movements , researchers reveal online today in Acta Palaeontologica Polonica. None of the fossils of those more-recent species of oviraptors include feathers, but those soft tissues are probably missing because they weren't preserved, not because they weren't there to begin with, the researchers contend. The most likely use for a feather-tipped tail is for courtship display, as depicted in this artist's reconstruction of a 1.5-meter-long male oviraptor Ingenia yanshini flirting with a potential mate.
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