Archaeopteryx that in an ostrich (4.2 micrometres per day). Using this range of bone growth rates, they calculated how long it would take to "grow" each specimen of "Archaeopteryx" to the observed size; it may have taken at least 970 days (there were 375 days in a Late Jurassic year) to reach an adult size of . The study also found that the avialans "Jeholornis" and "Sapeornis" grew relatively slowly, as did the dromaeosaurid "Mahakala". The avialans "Confuciusornis" and "Ichthyornis" grew relatively quickly, following a growth trend similar to that of modern birds. One of the few modern birds that exhibit
Ruppert Archaeopteryx Ruppert Archaeopteryx The Ruppert Archaeopteryx () is a Swiss high-wing, pod-and-boom, single-seat, microlift glider that was designed by Roger Ruppert and is produced by Ruppert Composite GmbH. The aircraft is named for the feathered Archaeopteryx dinosaur. The Archaeopteryx was conceived as a foot-launchable microlift sailplane, with the design goals of a light empty weight, low stall speed with gentle stall characteristics, good maneuverability and good high speed performance. A further goal was a sailplane that could be foot-launched in zero wind conditions. The Archaeopteryx design started in 1998 at the Zurich University of Applied Sciences (ZHW) as a research project.