was cooler and with a more balanced supply of moisture than today. During the Last Glacial Maximum, the mean annual temperature decreased from down to degrees, and annual precipitation had decreased from down to . This region was unaffected by the climatic effects of the Wisconsin glaciation and is thought to have been an Ice Age refugium for animals and cold-sensitive plants. By 24,000YBP, the abundance of oak and chaparral decreased, but pines increased, creating open parklands similar to today's coastal montane/juniper woodlands. After 14,000YBP, the abundance of conifers decreased, and those of the modern coastal plant communities, including oak woodland, chaparral, and coastal sage scrub, increased. The Santa Monica Plain lies north of the city of Santa Monica and extends along the southern base of the Santa Monica Mountains, and 28,000–26,000YBP it was dominated by coastal sage scrub, with cypress and pines at higher elevations. The Santa Monica Mountains supported a chaparral community on its slopes and isolated coast redwood and dogwood in its protected canyons, along with river communities that included willow, red cedar, and sycamore. These plant communities suggest a winter rainfall similar to that of modern coastal southern California, but the presence of coast redwood now found to the north indicates a cooler, moister, and less seasonal climate than today. This environment supported large herbivores that were prey for dire wolves and their competitors. Prey A range of animal and plant specimens that became entrapped and were then preserved in tar pits have been removed and studied so that researchers can learn about the past. The Rancho LaBrea tar pits located near Los Angeles in Southern California are a collection of pits of sticky asphalt deposits that differ in deposition time from 40,000 to 12,000YBP. Commencing 40,000YBP, trapped asphalt has been moved through fissures to the surface by methane pressure, forming seeps that can cover several square meters and be deep. The dire wolf has been made famous because of the large number of its fossils recovered there. Over 200,000 specimens (mostly fragments) have been recovered from the tar pits, with the remains ranging from Smilodon to squirrels, invertebrates, and plants. The time period represented in the pits includes the Last Glacial Maximum when global temperatures were lower than today, the Pleistocene–Holocene transition (Bølling-Allerød interval), the Oldest Dryas cooling, the Younger Dryas cooling from 12,800 to 11,500YBP, and the American megafaunal extinction event 12,700YBP when 90