Origin of birds mitochondrial uncoupling protein, UCP1, which is thermogenic. In mammals, UCP1 functions within brown adipose tissue to protect newborns against hypothermia. In modern birds, skeletal muscle serves a similar function and is presumed to have done so in their ancestors. In this view, bipedality and other avian skeletal alterations were side effects of muscle hyperplasia, with further evolutionary modifications of the forelimbs, including adaptations for flight or swimming, and vestigiality, being secondary consequences of two-leggedness. "Archaeopteryx" has historically been considered the first bird, or "Urvogel". Although newer fossil discoveries filled the gap between theropods and "Archaeopteryx", as well as the gap
Aathal Dinosaur Museum Dinosaurs, Archaeopteryx, eggs and embryos and footprints, as well as meteorites and minerals of "Siber + Siber". The collection includes 10 skeletons being finds from excavations by the museum's team, 10 further original skeletons from Dino, air and marine saurians, 19 detached skeleton fossil dinosaur replicas as well as 31 life-size dinosaur models and 42 replicas of dinosaurs and dinosaur skulls. In 2012 there were 437 guided tours, of which about three hundred for school classes, and since 1992 about 1,571,012 visitors. The staff of the museum consists of approximately 33 employees, of which six are members of the paleontological-scientific