In a few cases, amber has preserved spiders' egg sacs and webs, occasionally with prey attached; the oldest fossil web found so far is 100 million years old. Earlier spider fossils come from a few lagerstÃ¤tten, places where conditions were exceptionally suited to preserving fairly soft tissues.
Definition of METATARSAL. : of, relating to, or being the part of the human foot or of the hind foot in quadrupeds between the tarsus and the phalanges that in humans comprises five elongated bones which form the front of the instep and ball of the foot. See metatarsal defined for kids.ADVERTISEMENT. of, relating to, or being the part of the human foot or of the hind foot in quadrupeds between the tarsus and the phalanges that in humans comprises five elongated bones which form the front of the instep and ball of the foot. See metatarsal defined for kids. ADVERTISEMENT.
Metatarsal Stress Fractures â Treatment and Prevention. A stress fracture is a break in a bone that is caused by repetitive stress. It may occur in any bone, but is quite common in the metatarsal bones of the foot. A stress fracture usually starts as a small crack in the outer shell (the cortex) of the bone. Without proper treatment, this may progress to fracture all the way through the bone.