It is only known from a single specimen collected and described in 1844.

Only a single specimen, collected in the 19th century, is known.

The species was described in 1895 from a single female specimen.

It is known from only a single specimen, collected in the 1950s.

A single specimen of that issue can go for $50,000 to $200,000.

Until recently, only a single specimen from this family was known.

It was discovered in 1981 and the single known specimen has since died.

In general, the family is considered rare, with close to 95% of the species known to have been described from single specimens.

It is known only from a single specimen, a male.

Each as based on a single specimen, and they were found very close together.