Something rarely seen on Harvard’s sidewalks: dinosaurs, starfish, and mollusks. In chalk, that is.

Yesterday, on a bright and sunny afternoon, Sidewalk Sam, a Boston-based artist most recognized for his chalked sidewalk murals, collaborated with Harvard Museum of Natural History to draw a timeline of the earth’s 4.6 billion year history and the diversity of life forms that existed during these eras.

The mural project began to materialize when a graduate student in paleontology, Ben Kotrc, met Sidewalk Sam during the summer at an event. The project attracted young children of all ages and encouraged students to marvel at the foreign life forms created by the artist and other collaborators.

The fossils were drawn in distinctive hues such as saturated blue, orange and yellow, and drew the attention of many passers-by. While the depictions of these fossils are inaccurate as far as the color scheme is concerned, they nevertheless add a colorful flourish to what some may find stodgy subject matter.

“We want the Harvard community to think like naive third graders again,” said Sidewalk Sam. His desire to reignite a sense of wonder and engagement in the history of the natural universe certainly echoes the wishes of the life science community at Harvard.

“We want to get people at Harvard more enthusiastic and involved in the Life Sciences,” said Hann-Shuin Yew ‘10, a Molecular and Cellular Biology concentrator and a member of the Harvard Undergraduate Biological Sciences Society.

The mural will undoubtedly disappear with the elements, but its creators say they hope any observer’s newfound curiosity in natural history won’t fade away with it.