Plotopteridae they became extinct. That they became extinct at the same time as the giant penguins of the Southern Hemisphere, which also coincided with the radiation of the seals and dolphins, has led to speculation that the expansion of marine mammals was responsible for the extinction of the Plotopteridae, though this has not been formally tested. Plotopteridae Plotopteridae is the name of an extinct family of flightless seabirds from the order Suliformes. Related to the gannets and boobies, they exhibited remarkable convergent evolution with the penguins, particularly with the now extinct giant penguins. That they lived in the North Pacific, the
Southern Hemisphere Auroral Radar Experiment Southern Hemisphere Auroral Radar Experiment The Southern Hemisphere Auroral Radar Experiment (SHARE), started 1988, is an Antarctic research project designed to observe velocities and irregularities of electrical fields in the ionosphere and magnetosphere. SHARE is operated jointly by the University of Natal, Potchefstroom University, the British Antarctic Survey and Johns Hopkins University and operates out of British Halley Station, South African SANAE IV Station and Japanese Showa Station. Using a total of 16 antennas, each mounted on a 12 m tower and radiating on fixed frequencies in the 8–20 MHz range, SHARE transmits an RF pulse into the upper atmosphere