<p>Scientists are on the look-out for "lost amphibians" animals considered possibly extinct but that may be holding on in a few remote places. There may be up to 100 of them hiding in the world's forests.</p> <p>Here are just a few of the many fascinating amphibian species who have not been seen for over a decade. Some may be lost forever, while others may still exist, hidden under rocks in a remote stream, waiting to be rediscovered.</p>
<p>The Golden toad was last seen in 1989 and is perhaps the most famous of the lost amphibians. The species went from abundant to extinct in a little over a year in the late 1980s.</p> <p>Golden toads were originally discovered in 1966 in western Costa Rica's Monteverde Cloud Forest, where populations of other amphibian species have also collapsed, a development thought to be linked to climate change and disease.</p>
<p>Gastric brooding frogs come in two species: Rheobatrachus vitellinus and R. silus (pictured above and last seen in 1985).</p> <p>These frogs had a unique mode of reproduction: Females swallowed eggs, raised tadpoles in their stomaches and gave birth to froglets through the mouth.</p> <p>The reason for the frogs' decline is unknown. Timber harvesting and the chytrid fungus are the main suspects.</p>
<p>This frog with a distinctive pyramid-shaped head was last seen in 1914.</p>
<p>This black and yellow salamander one of only two known specimens is believed to have been stolen from a California laboratory in the mid 1970s was last seen in 1975.</p>
<p>Very little is known about this animal which is never thought to have been photographed. It resides in high-altitude forests, especially bamboo forest, but the frog hasn't been recorded since 1950, possibly due to a lack of field work in the area</p>
<p>Last seen in April 1995 and may well have been wiped-out by chytridiomycosis.</p>
<p>Last seen in 1909 and known from only two specimens collected that year. All the collected specimens have since been lost and no other records are known.</p>
<p>The Scarlet frog was last seen in 1990 and is known only from a single stream in an isolated cloud forest.</p>
<p>The Hula painted frog was last seen in 1955 when a single adult was collected. Efforts to drain marshlands in Syria to eradicate malaria may have been responsible for the disappearance of this species.</p>
<p>Last seen in the 1950s, increased sedimentation in streams after logging may have contributed to this toad's decline.</p>
