Thanks to a researcher from U.K.'s Natural History Museum and a King Island historian, a strikingly large egg of a dwarf emu, which is a short and stocky bird that went extinct about 200 years ago, has been unearthed in "rare" and "unique" discovery from a sand dune on King Island, located between Australia and Tasmania.
The study, published in the journal Biology Letters, is helping scientists learn more about the now-extinct dwarf emus and how their eggs evolved to safeguard the baby birds within.
A beautiful, almost complete emu egg found in a sand dune
Emus are the world's second-largest bird, towering 5.7 feet (1.7 meters) tall on average, and though Australia and its neighboring islands today only have one species of emu, this wasn't always the case. According to Phys.org, there were at least three other subspecies of emus, the smaller Tasmanian emu (D. n. diemenensis), the dwarf Kangaroo Island emu (D. n. baudinianus), and the dwarf King Island emu (D. n. minor), residing on these islands before the European settlers arrived. They were then driven to extinction as a result of overhunting after European colonization began.
Julian Hume, a paleontologist and research associate at the National History Museum in London who is the study lead researcher, told Live Science that the emu species split roughly 11,500 years ago, when melting glaciers raised sea levels and isolated the islands from the Australian mainland. Species isolated on an island tend to shrink over time, and the dwarf emus were no exception, with the smallest of the subspecies being located on the King Island, which stood less than approximately 3 feet tall (a meter) and weighted the half of a modern emu.
Up until now, no egg belonging to the King Island emus had been found. The egg was discovered in a sand dune by study co-author Christian Robertson, a natural historian on King Island, according to Hume. "He found all the broken pieces in one place, so he painstakingly glued them back together and had this beautiful, almost complete emu egg," he said. "The only one known in the world [from the King Island dwarf emu]."
What's interesting is that, despite the adult emus' size differences, their eggs were nearly identical in size. This could be because its offspring needed to be large enough to maintain body heat and robust enough to seek food soon after hatching. While researchers want to learn more about the evolution of the King Island dwarf emu, its quick extinction and the removal of its remains for a golf course are major setbacks.
“This scenario provides an interesting evolutionary response to insular environmental conditions in dwarf emu breeding strategy, but due to their complete and rapid extinction, the true extent of these adaptations is now impossible to determine," the researchers wrote.