Stuck! The story of La Brea tar pits

Like a sort of prehistoric rubbish bin filled to the brim, the sticky La Brea Tar Pits have been "collecting" victims and natural detritus since the Pleistocene epoch. Here, Uglow invites readers to marvel at the amazing bulk and diversity of the well-preserved lode--over 3.5 million specimens, from microfossils to megafauna, have been extracted to date--and think about what researchers can learn from, as she puts it, an "entire ecosystem jumbled together," including "unlucky predators and prey in stacks." Along with cross-sectional views of thick subsurface tangles of bones, bugs, and plant material, Milovanova depicts both reconstructed ancient scenes of a giant ground sloth, dire wolves, and other dismayed, now-extinct creatures stuck in black tar and of modern workers systematically excavating and reconstructing skeletons. The author closes with more on how the tar pits were formed and have been explored, accompanied by an eye-widening list of plant and animal species that have been found in them. "The Tar Pits time capsule tells millions of stories," she writes, and cannot fail to "fill our hearts with wonder."

Uglow's rhythmic text traverses thousands of years as it tells the prehistoric tale of many fossils coming to exist in Los Angeles's La Brea Tar Pits. At book's opening, an unsuspecting Harland's Ground Sloth accidentally enters the pits' "oozing, oily stickiness," followed by hungry predators that also become stuck, eventually forming "menageries trapped together/ under seeping asphalt and sediment." A spread zips forward to the moment when oil field workers discover a "time capsule" of bones hiding within the pits, providing scientists with a window into the past. Washed in muddy hues, Milovanova's free-form illustrations include markings that seem scratched into each page's coloring--an apt approach given scientists' work to peer beneath the pits' surface in search of the region's prehistory. Back matter includes a glossary. Ages 7--10. (Mar.)