Egg embryo is adequately developed it hatches, i.e. breaks out of the egg's shell. Some embryos have a temporary egg tooth they use to crack, pip, or break the eggshell or covering. The largest recorded egg is from a whale shark, and was in size. Whale shark eggs typically hatch within the mother. At and up to , the ostrich egg is the largest egg of any living bird, though the extinct elephant bird and some dinosaurs laid larger eggs. The bee hummingbird produces the smallest known bird egg, which weighs half of a gram (around 0.02 oz). Some eggs laid
Sri Lanka spurfowl species of bird in the genus "Galloperdix". It is a ground nesting bird, which lays 2-5 eggs in a scrape. Sri Lanka spurfowl is ~ 37 cm long bird. Both sexes have brown upperparts, wings and tail. The males exhibit vivid crimson red legs and bare facial skin and striking black and white dorsal plumage that extends to its head. There is also extensive white ocellation on the sepia wings and upperback. The legs of both sexes have multiple metatarsal spurs, which give rise to the specific name. The female has chestnut underparts and a plain brown back and wings.