Tuesday’s Google Doodle marks the discovery of “Lucy”, a skeleton found 41 years ago in Ethiopia that helped scientists understand the evolution of apes into bipedal humans.

Named after the Beatles song “Lucy in the Sky With Diamonds,” the 3.2 million-year-old remains belong to the Australopithecus afarensis family, a species that shares both human and ape characteristics, according to the Telegraph.

Almost 40% of Lucy’s skeleton remained intact — a particularly rare occurrence given most fossils of that age are found shattered and fragmented — allowing researchers to study the distinct curvature of her spine and her knees and uncover her ability to walk upright, the Independent reports.

The Doodle shows an Australopithecus afarensis walking between a chimpanzee and a human, marking the transition between the two species.

[The Independent]

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.