The egg was a "rare" and "unique" discovery, lead study author Julian Hume, a paleontologist and research associate with the National History Museum in London, told Live Science. For the first time, scientists have found and described an egg belonging to an extinct species of dwarf emu that only lived on one Australian island.
What are Emus?
Emus are the world's second largest bird, measuring an average of 5.7 feet tall, according to the Smithsonian. There is currently only one species of emu that lives on Australia and its surrounding islands, but this was not always the case.
How did Dwarf Emus get Extinct?
Before European settlers arrived, there were at least four different subspecies of emus living on different islands off the Australian coast. 1. Dromaius novaehollandiae
2. Smaller Tasmanian emu (D. n. diemenensis)
3. The dwarf Kangaroo Island emu (D. n. baudinianus)
4. The dwarf King Island emu (D. n. minor). Sadly, all three went extinct shortly after European colonization began. Hume told Live Science that the emu species diverged around the end of the last ice age some 11,500 years ago, when melting glaciers increased sea levels and separated the islands from the Australian mainland. It is an evolutionary rule that species isolated on an island tend to shrink over time, and this was the case for the dwarf emus.
The finding wasn't just unique in its own right; it enabled the scientists to compare all of the extinct emu eggs they were aware of, including six from Tasmania and one from Kangaroo Island. They discovered that, despite the birds' smaller size, the eggs had roughly the same dimensions as today's larger emu eggs, though they were slightly less in mass and volume and appeared to have slightly thinner shells, the study explained.
Dwarf Emus's fail in Evolutionary Strategy
Hume told Live Science that retaining a larger egg size could help the dwarf emus on two fronts: it would protect the eggs from predators and give the baby birds time to fully develop before emerging from the shell. This is a similar evolutionary strategy to New Zealand's kiwi, which lays the largest egg relative to body size in the world. Read all trending updates here.