Respiratory effects [edit]. The PRG antagonizes the apneustic center, cyclically inhibiting inhalation. The PRG limits the burst of action potentials in the phrenic nerve, effectively decreasing the tidal volume and regulating the respiratory rate.espiratory effects [edit]. The PRG antagonizes the apneustic center, cyclically inhibiting inhalation. The PRG limits the burst of action potentials in the phrenic nerve, effectively decreasing the tidal volume and regulating the respiratory rate.
Because the ones at the bottom, the animals would have died first and soil would have covered them building a cliff and the fossils up top would have died later. 3 people found this useful.
Archaeopteryx is an early prehistoric bird, dating from about 150 million years ago during the Jurassic period. Consequently, it is considered by many to be the oldest known bird. Archaeopteryx shares both the features of theropod dinosaurs as well as modern birds.It is thus widely considered a transitional fossil between the birds and reptiles. In many ways, Archaeopteryx is more similar to small theropod dinosaurs than it is to modern birds.However, the evolutionary history of Archaeopteryx has never been that simple.ertebrae, Tail: The tail of Archaeopteryx is unlike that of modern birds, in that it is long and possesses several individual vertebrae. Those of modern birds are generally much shorter and contain fused vertebrae (Nedin 1999).