Only five specimens of these three species have been recovered.
Recently, a few additional specimens of his writings were recovered.
Some 100 specimens have been recovered and displayed in American museums.
Only one specimen of Animantarx has so far been recovered.
Additional live specimens recovered in 2010 and 2011 from Oregon were all found deep inside caves.
While earlier specimens have been recovered from north Africa, how the species evolved and spread is still uncertain.
In 2005, a second, more complete specimen was recovered from the same locality and horizon.
Although no official specimens were recovered until 1970 it is understood that members of the local Aboriginal community had collected pieces.
During this time frame (1902-1915), two additional important specimens of C. annectens were recovered.
Nine specimens have been recovered at this site.