A coil of teeth caps the lower jaw of a sculpture of a 13-foot (4-meter) whorl-tooth shark, or Helicoprion, a fish genus that lived about 250 million years ago. Artist Gary Staab depicts the animal’s jaw as something of a spiral conveyor belt, in which new teeth would advance to replace old ones (concealed here by skin) . But the true arrangement and purpose of the teeth remains a mystery. Some scientists suggest that it may have operated like a spiked whip, possibly curled underneath the lower jaw like a weaponized elephant trunk. The shark adds bite to “Bizarre Beasts, Past and Present,” a new exhibition of Staab’s sculptures at the National Geographic Museum in Washington, D.C. (through February 2, 2007). The animals depicted are, or were, all real testaments to the twists, turns, and blind alleys of evolution.
So new to science that it hasn’t even been named yet, this African pterosaur lived alongside dinosaurs about 110 million years ago in the Cretaceous period. Nail-like teeth and a 16-foot (5-meter) wingspan likely helped the flyer catch and hold onto fish from African rivers, according to University of Chicago paleontologist Paul Sereno, whose team discovered the species in the Sahara of Niger.
Extinct ancestor of today’s hogs, this Archaeotherium—”ancient beast”—lived some 23 to 34 million years ago in what is now South Dakota. Strong neck muscles suggest that the roughly 4-foot-long (120-centimeter-long) animal was well suited to digging up roots and tubers with its snout.
They call 55-million-year-old Diatryma gigantean a terror bird. And the evidence is compelling. This flightless species stood some seven feet (two meters) tall and was armed with a strong beak and powerful clawed feet. In North America and western Europe, scientists say, Diatryma likely took over as top predators once the dinosaurs had died off possibly even hunting ancestors of today’s horses.
Source: National geographic