In September, a team of scientists, led by paleoanthropologist Zeresenay Alemseged, announced the results of a study on the 3.3-million-year-old skeleton of an ancestor of human beings called A. afarensis. The skeleton, found in Ethiopia, appears to be that of a 3-year-old girl. Selam, as she is called, is now the oldest hominid fossil on record. She belonged to the same genus and species as the famous “Lucy,” and despite being 100,000 years older, received the contentious nickname “Lucy’s Baby.” Scientists are using Selam to uncover details about the development of brain capacity and bipedal locomotion. When the news broke in the September 21 issue of Nature, however, Scientific American’s news lineup was packed, and with a two-month lead time the editors could not squeeze it into the magazine. So they decided to try an experiment that they had been kicking around for months.

“Immediately, we knew we wanted to do more with it than usual,” said SciAm’s online editor, Kate Wong, who had been following the Lucy’s Baby story. The day before Alemseged’s paper was published, Wong had written a feature-length article for the magazine’s Web site describing the Selam discovery and the significance of what scientists had already learned from her bones. Next to it was a sidebar that urged readers to “Be part of our publishing experiment.” The note explained that another version of the story would appear in the December issue of Scientific American magazine, and solicited feedback from readers about what information the new article should contain. There was a link to a blog where readers could post comments and questions about Selam’s discovery and the subsequent research. Wong also contacted a number of experts in the fields of paleoanthropology and human evolution (some of whom she had already interviewed for the online article) to ask for their input as well. “We just crossed our fingers that people would be interested enough to comment on this,” Wong said. “Fortunately for us, they were.”

Throughout September and October, more than 100 readers and six scientific experts posted their thoughts on the SciAm blog. Two weeks ago, the results of the experiment, the second iteration of Wong’s feature on Lucy’s Baby, hit the newsstands. The front of the December issue contains an editors’ note, titled “Old Baby in the New Media,” which explains the genesis and evolution of Wong’s story. “Wikis, social bookmarking and other online exercises in communal authorship have opened eyes to novel ways of creating quality content,” it reads.

John Rennie, SciAm’s editor-in-chief, said last week that for some months the staff had been “trying to develop features for both Web site and print that would play to the strengths of each medium.” When the Lucy’s Baby story got jammed in the news pipeline, it provided the perfect opportunity. Colorful graphics of Selam’s skeleton and maps of the excavation site were a good fit with both digital and traditional platforms, and the magnitude of the discovery left readers plenty of room to ask follow-up questions about Wong’s first take on the story.

There are about four new paragraphs in the eight-page December feature, and some subtle reshaping of the existing text. When the story broke in September, readers immediately took issue with the nickname “Lucy’s Baby,” which they called misleading because Selam is much older than Lucy. In response, Wong added a parenthetical statement to the first paragraph of her print feature that acknowledged the contradiction. Readers also wanted more detail about how scientists dated the skeleton and determined its sex. Having that feedback was useful, according to Wong. “I wasn’t clear that that was something the reader wanted to know,” she said. “And I don’t know if I would’ve included that amount of detail.”

Curtis Brainard writes on science and environment reporting. Follow him on Twitter @cbrainard.