During the last few million years, as the coast ranges of western North America were pushed up, natural oils collected in the rwisted rock structures below ground and formed reservoirs of petroleum. In some places, as the rocks twisted and cracked, the oil seeped to the surface and spread out forming sticky pools. In the open air, the volatile components of the crude oil evaporated and left behind a layer of viscous asphalt or tar. This is how the tar pits of Los Angeles,USA originated. realistic dinosaur costume
Rains came, and formed pools of water on top, and from a distance these pools looked, to animal life, like refreshing watering holes. Animals came to drink, and once they had waded into the pools they became enmired in the tar beneath and could not escape. Predatory animals in the area converged on these spots to feed on the captive beasts, and often became trapped themselves. In this way the situation resembled that found in desert oases and streams, except instead of river quicksand trapping the animals, the danger was formed by natural deposits of tar. In both cases the result was a “predator trap” in which animals that came to feed on trapped animals became trapped themselves.
Even in dry seasons when water was not present as an attraction, the tar pits were a danger. They were disguised by wind-blown dust and leaves，which would stick to the surface. The warmer weather made the rar sticky, and unsuspecting animals wandering across it became quickly hogged down. animatronic dinosaur
The bones that sank into the tar were well preserved, although stained dark brown by the asphalt chemicals. Those left on the surface were weathered by heat, cold, wind and rain. They were also damaged by the gnawing of rodents that somehow escaped entrapment themselves. Similar tar pits arc found in Peru and Iran.
Belova: The tar pits of Los Angeles are a cluster of pits that contain an incredibly rich and diverse collection of fossils of animals, insects, and plant life that existed 40,000 years ago.