title: Promecognathus
text: # Promecognathus
  
  Promecognathus is a genus of ground beetles in the family Carabidae. There are at least two described species in Promecognathus. Both species of Promecognathus are known to predate upon Xystocheir dissecta, which is a species of flat-backed millipede that produces cyanide as a chemical defense. The beetles do not avoid exposure to the defense, meaning they are likely physically resistant to cyanide.
  
  ## Species
  
  These two species belong to the genus Promecognathus:
  
  * Promecognathus crassus LeConte, 1868
  * Promecognathus laevissimus (Dejean, 1829)
  