Ancient Fossils: A Story of Life’s Evolution

★Travel Location: Shanghai Oriental Geology Science Museum

Our Earth is 4.6 billion years old. Across its long history, it has been home to as many as 500 million species. However, because of dramatic geological and environmental changes, there have been several mass extinction events. Old species died out and new ones emerged. After ancient life perished, it was often quickly buried underground. Normally, soft tissues would rot away, while the hard parts could become fossilized through mineralization—the original materials were replaced by minerals, turning them into fossils.

The Shanghai Oriental Geology Science Museum houses not just rocks of all sizes, but also an impressive collection of fossils. Some belong to animals we know well, like trilobites, ammonites and crinoids (sea lilies). Many more are the remains of creatures we’ve never heard of.

Take the bone-lip fish (Osteoglossiformes). It lived in the Eocene, around 40 million years ago, and belongs to the carp family. Shaped like a spindle, it does somewhat resemble the carp of today. The fossils here are arranged in five rows of five—except the last row, which has one missing—so there are 29 specimens in total. It made me think this fish was common, but actually it is quite rare; the museum just happens to have abundant resources.

The bizarre crayfish (Mecochirus) was an invertebrate from the Late Jurassic to Early Cretaceous. Its head and thorax were large and cylindrical, with a well-developed rostrum. The first pair of legs formed crab-like claws, and two other pairs also had pincers—quite unlike modern shrimp. The fourth and fifth legs were claw-shaped. Its tail fan looked like butterfly wings, somewhat reminiscent of the crayfish popular on dinner plates today.

A replica of the Sinosauropteryx fossil is on display—the original is priceless. Its name contains both “dragon” (long) and “bird,” leaving people wondering: is it a dinosaur or a bird? When the fossil was first discovered, the debate was fierce. Later, scientific analysis confirmed that Sinosauropteryx is a small theropod dinosaur, a type of compsognathid. According to reconstructions, it had no wing-like structures. As for the hair-like feathers on its body, some believe they might be “ornaments” indicating gender, while others think they served as insulation. If the latter is true, then small dinosaurs like Sinosauropteryx might have been warm-blooded, perhaps even endothermic.

There is also a creature I’d never heard of: the tubeworm Rotularia. According to the introduction, it lived from the Jurassic to the Paleocene and was found in Indonesia. The fossils suggest a small, worm-like or possibly planktonic animal.

The Hezheng sheep fossil is incomplete—its leg bones are the clearest. This bovid was discovered in the Hezheng area of Gansu Province. In size and appearance it resembles modern sheep, yet the skull structure, horn shape and neck features are closer to the muskox. Today, muskoxen live only in Alaska, North America. The discovery of Hezheng sheep suggests that muskoxen actually originated in Asia and later migrated to North America across the Bering land bridge.

Platybelodon was an ancient animal that lived over ten million years ago. Seeing its teeth, you can’t help but marvel: this was indeed a famous large land mammal. The ancestors of today’s African and Asian elephants, Platybelodon went extinct when forests gave way to grasslands due to climate change. Its extinction, unlike that of the dinosaurs, isn’t shrouded in as many competing theories.

Stegodon lived 12 to 1 million years ago across Asia and Africa. Compared to modern elephants, its legs were longer and its tusks even larger. The tusks were like two huge halberds, though some Stegodon species had tusks that curved sharply at the tips, similar to a mammoth’s.

The Nanxiong turtle fossil is just a shell. This turtle was huge, the most striking feature being the net-like pattern on its bony plates. It lived in the Cretaceous period. Because it was unearthed in Nanxiong, paleontologists named it “Nanxiong turtle.”

The oil Malay crocodile lived in the late Eocene and was found in the Maoming oil shale layers of Guangdong. The texture of its skin looks very similar to that of today’s crocodiles.

The shieldless Maoming turtle was also discovered in the Maoming area. This turtle was much smaller and lived in the middle to late Eocene. Its shell had a relatively high central dome.

The Guizhou dragon was discovered in Guizhou. Its shape bears a striking resemblance to the “dragon” of Chinese legend: a long, slender body with four limbs and a tail. When first found, it was called a “four-footed snake.” This dragon could not fly; it was a reptile.

The ancient three-bodied crab comes from Argentina and lived in the Miocene. Its carapace is nearly hexagonal, with stout pincers of different sizes and strong walking legs. The fifth pair of limbs, however, is slender and flat, apparently adapted for swimming.

The museum also has a large number of fish and plant fossils, though most are relatively common species. The sea lily is the most beautiful in shape and is displayed in many museums.