Thylacinus cynocephalus goes by many common names: Tasmanian wolf, Tasmanian tiger, zebra dog, pouched wolf, and marsupial dog, among others. A quick look at the animal explains the confusion. Shaped like a dog, striped like a tiger or zebra, pouched like an opossum, and reputed to behave like a wolf, it became many different creatures in the popular imagination.

But the thylacine is, or was, a unique species. Now considered extinct, the thylacine was a carnivorous marsupial that lived in Tasmania and fed primarily on kangaroos, wallabies, small mammals, and birds. Nocturnal and shy, it was seldom seen by humans. Nonetheless, beginning in the 19^th century, settlers believed the animals threatened their livestock and, spurred on by a bounty offered by the government, hunted them relentlessly. Despite numerous unconfirmed reports of sightings in recent decades, no definitive sightings have occurred since the 1930s.

They are some of the rarest of rare artifacts: fossil dinosaur eggs with the embryo still inside. And they are prized for what they can tell paleontologists about the adults that laid them.

The exhibition The World’s Largest Dinosaurs features a scale model of a nest found at Auca Mahuevo, Argentina, one of the largest known dinosaur nesting sites in the world. While it isn’t always possible to figure out which dinosaur laid a particular egg, in this case, an embryo within an egg found at Auca Mahuevo site allowed scientists to identify these eggs as those of titanosaurs, a group of sauropods that included such species as Ampelosaurus and Saltasaurus. Herds of female titanosaurs are thought to have laid the thousands of eggs — 15 to 40 at a time — in shallow nests dug out with their huge feet in dry mud and sand over miles of ground at Auca Mahuevo.

Almost every star is now thought to form with a planetary system around it. But just how rare a phenomenon are habitable planets? In this podcast, Massachusetts Institute of Technology professor Linda Elkins-Tanton discusses what is currently known about planetary formation—and what is needed to encourage the development of life.

Dr. Elkins-Tanton’s talk, “A Hitchhiker’s Guide to Habitable Planets in Our Galaxy,” was recorded at the Museum on April 11, 2011.

In the wake of the devastating earthquake that struck Haiti last year, a group of U.S. scientists flew to Port-au-Prince to complete the first technical survey of the city’s geology. A film crew from Science Bulletins, the Museum’s innovative online and exhibition program, joined them to document the fieldwork, producing an Earth Bulletin now on view in the David S. and Ruth L. Gottesman Hall of Planet Earth and online on the Museum’s website.

“The earthquake in Haiti was such a momentous event that we felt we had to talk about the science behind it,” says Edmond Mathez, curator in the Museum’s Department of Earth and Planetary Sciences and the curator for Earth Bulletins.

Since 1990, scientists from the American Museum of Natural History have traveled to Mongolia’s vast Gobi Desert each summer in search of fossils, continuing a tradition of Museum expeditions to the region that began in the 1920s. In 1993, Museum researchers working with Mongolian scientists uncovered one of the richest fossil beds ever found: Ukhaa Tolgod. The site produced hundreds of dinosaur, lizard, and mammal fossils from the Cretaceous period.