Advent of Hominins. Day Seven-AL-288

A.L.-288-1

It is hard to discuss the relevance of A.L.-288-1 (aka Lucy) in only a few words. There is little doubt that Lucy is one of the most famous hominin fossils ever found. The story of its discovery by Tom Gray & Don Johanson, has been told in countless places, including a best-selling book. Rather than even attempt to do her justice, here are just a few facts that might not be as well known

If you want to know all about Lucy I highly recommend reading the irreplaceable Caitlin Schrein’s article “Lucy: A marvelous specimen” as it pretty much covers all you need to know (and more) about Lucy.

  • In the Amharic language, the fossil is called Dinkinesh which means “you are marvelous”

commerative 20 Birr coin. Image from https://en.numista.com/catalogue/pieces43464.html

  • She is named after the Beatles song “Lucy in the Sky with Diamonds.” It took me way too long to figure how to embed a video in a Markdown document so just in case you want to hear the music!
  • Depending upon how you count up the bones, about 40% of Lucy’s bones have been recovered. One interesting story is that of the vertebrae A.L. 288-1am. It was first thought to be an upper thoracic vertebrae (the ones that support the ribs) but recent work by Marc Meyer and colleagues shows that it actually belonged to a baboon! Since its general mohpoloy looks like a catarrhine (a Parvorder consisting of monkeys from Africa, Asia, and Europe, plus the apes), and since the preserved portions were not very informative, it went unnoticed until scholars reexamined the fossils. If you get the chance read their paper. It is an amazing detective story and a great lesson in anatomy

  • Estimates of stature are tricky since they often involve large error ranges. That being said Hher total stature is estimated to be ~104-6 cm tall ( ~3.4 feet). Since she reached full adulthood that seems tiny compared to modern humans (she was ~ 64% the height of the average American woman). Check out this comparison between an 8-year-old I happen to know and Lucy.

  • The ratio of her humerus to her femur is ~.85, intermediate between humans and chimps. In general bipeds have relatively shorter arms than legs. Bill Jungers and others have suggested that the hominin humerus got smaller before the femur got longer.

  • Al-288-1’s scapula is oriented towards the cranium, a signal of an apelike-shoulder. However, some researchers have noted that a superior orientation of the glenoid cavity is seen in smaller-bodied humans

  • Her pelvis seems mostly adapted to bipedalism. the ilium (the upper part) of the pelvis is short and broad, a signal of the gluteal muscles being adapted for bipedalism. The image below shows a chimp, Lucy, & a Homo sapiens pelvis compared (from Heaton 2016 Human Origins and Evolution in the Neogene)

  • the AL in her catalog name refers to Afar Locality. Hadar, the region within Afar triangle in which Lucy was found, is the site of many important fossil finds.1

  1. My second daughter’s middle name is Hadarah, which is a Hebrew name meaning “Adorned with beauty.” The fact that it is very similar to Hadar is, of course, a complete coincidence…↩︎