These dead passenger pigeons are from the archives of the Field Museum of Natural History. The Chicago museum holds many dead animals -- many of which are extinct or on the way to being extinct. The passenger pigeon was once one of the most prominent bird species in eastern North America. But deforestation and reckless hunting brought its population close to zero. The last one died at the Cincinnati Zoo in 1914.
As new specimens are entered into the museum's fish collection, they are tagged with a unique number from this roll.
The plateau chub is one of the extinct fish species at the museum. Photographer Marc Schlossman said he tried to compose his images with the "simplicity of a police mugshot." Like you're looking at the specimen without museum glass as a barrier.
The Cuban ivory-billed woodpecker, now thought to be extinct, was last seen in the 1980s. Deforestation devastated its habitats and its primary food source (large beetle larvae). By the 1950s, the bird was confined to an isolated area of pine forest in eastern Cuba, where its numbers continued to rapidly decline.
This shell is from a Charles Island tortoise, a subspecies of the Galapagos giant tortoise. It is now extinct.
The Xerces blue butterfly was last observed in the wild in 1941. The species was of great interest to butterfly experts because each specimen exhibited incredible variation in its wing patterns. It was native to the coastal sand dunes of San Francisco before losing its habitat to urbanization. It was the first North American butterfly to become extinct as the result of human action.
There are 41 species of tree snails that were once endemic to Hawaii but are now critically endangered or extinct. These tree-dwelling snails were once found in forests at high altitudes. They were nocturnal and fed on fungus that grows on the leaves of some native Hawaiian plants. The most commonly recognized culprit behind the extinction of Hawaiian tree snails has been the introduction of the invasive, aggressive and carnivorous Euglandina rosea, or the rosy wolfsnail. Native to Central America, the rosy wolfsnail was introduced to Hawaii in an attempt to control the population of another snail, the giant African land snail, which was causing damage to crops and plants.
The Grand Cayman thrush was once common on the Caribbean island of Grand Cayman. Its extinction is thought to be the result of habitat destruction due to deforestation and hurricane damage. The last confirmed sighting of the Grand Cayman thrush was in 1938.
The last known thylacine, or Tasmanian tiger, died in captivity in 1936. The dog-like marsupial could only be found on the Australian island of Tasmania, but thousands were eradicated after European colonists killed them for attacking sheep. Today the thylacine remains a major component of Tasmanian culture. It maintains almost Loch Ness Monster status, with regular claims of unsubstantiated sightings.
The decline of the blackfin cisco was caused by overfishing, predation and interbreeding. Occasional sightings are made in Lake Nipigon in Ontario and other localities, but they are disputed and thought by some authors to be sightings of lake herring.
Cyclosurus mariei is an extinct land snail. "When you see (species) lined up on a wall or one after the other on a website, there's a certain impact," Schlossman said. "It's almost like a row of things -- one story after another. Hopefully people will be affected by it in the way that I am. I open these drawers and I'm just kind of overwhelmed at the end of the day. I see things that are gone or almost gone."
Epioblasma is the fourth largest genus of North American mussels, made up of around 27 species of freshwater river mussels. It is believed that more than half of the species or subspecies found in this genus are extinct. The others are endangered.
The Atitlan grebe, also known as the poc, was a large, flightless bird endemic to Lake Atitlan in Guatemala's Sierra Madre mountain range. The species was first described in 1929 and declared extinct by 1990.
There are approximately 105 species of frogs native to the immensely diverse central highlands of Sri Lanka. Yet these figures change almost yearly. With ongoing research, frog species are constantly discovered, rediscovered and declared extinct. These are white-nosed bush frogs, one of the extinct species. The primary cause is speculated to be loss of habitat, most likely from the conversion of land to grow tea and rubber.