Two of the National Zoo’s thylacines, probably the surviving offspring of the original female, outside the Carnivora House, c. 1905. One of these animals (most likely the one in front) is USNM 125345, a specimen recently DNA-sequenced by a team of international scientists.
In the Australia exhibit of the National Museum of Natural History's Kenneth E. Behring Family Hall of Mammals, look beyond the dingo, and behind the gossamer fabric screen at the thylacine (Thylacinus cynocephalus), a rare mounted specimen of an extinct species of carnivorous marsupial that once lived throughout Australian continent, including the island of Tasmania. Printed on the screen is the title “An Extinction Story” and the question “What happened when these two predators faced off?” The dingo—a wild dog that arrived in Australia with Asian seafarers 3,500 years ago—and the thylacine, are not related species. However, as Australia's top predators, they shared a similar diet. As the dingo spread throughout the Australian continent, the thylacine disappeared, apparently surviving only on the isolated southern island of Tasmania by the time that European settlers arrived in Australia just over 200 years ago.
A poignant reminder of the reality of extinction, this mounted female thylacine lived at the Smithsonian's National Zoological Park from 1902 until her death in 1904. She was, to everyone's amazement, carrying three baby cubs in her pouch when she arrived; one of them died soon after, but her two remaining offspring (a male and a female) survived into adulthood—the last one dying just over 100 years ago, in 1909. All four—together with another male specimen who was brought to the Zoo in 1904, possibly for a (sadly unsuccessful) attempt at captive breeding—are now preserved in the National Museum of Natural History collections. Overhunting by European settlers and an unidentified disease led to the rapid decline of thylacines throughout Tasmania in the 1800s and early 1900s. The last known thylacine died in 1936 at the Hobart Zoo in Tasmania.
Thylacines, the largest modern marsupial predator, seemed from their outward appearance to be a mix of several animals. They had a series of brown stripes in the fur along their back that gave them one of their nicknames, the Tasmanian tiger. Their heads, teeth, and body shape were more reminiscent of a large dog—the origin of another common name, the Tasmanian wolf. Yet as marsupials, they had a pouch where they raised their young, and were only very distantly related to true tigers and wolves. Scientists consider the thylacine—an animal so unique that it is classified in its own phylogenetic family, Thylacinidae—to be a stunning example of convergent evolution with the dog family; the two unrelated mammal lineages, long isolated on different continents, evolving similar anatomical features and behaviors under similar ecological pressures.
The Smithsonian's thylacine specimens continue to be used in research today. Recently the National Museum of Natural History's zoologist Kris Helgen and an international team of researchers successfully mapped the full mitochondrial genome sequences of two thylacine specimens, which included one of the cubs brought to the National Zoo in 1902. They took most of their samples from the tufts of fur between the toes of the hind feet, so as to damage the historic specimens as little as possible. Their results provided detailed proof that the thylacine was in a phylogenetic family of its own. More importantly, they proved that very long stretches of DNA could be successfully recovered from an animal skin that had been stored at room temperature for a century! These exciting results opened the door to genetic analysis of virtually any specimen in the museum's collections—and underscored the significance of the Museum's historic collections. This work also represents a key step in helping scientists understand mammalian extinction events and hopefully preventing them from happening in the future.