1) Family xenosauridae 2) Reptile family 
Xenosauridae is a family of anguimorph lizards whose only living representative is the genus Xenosaurus, which is native to Central America. Xenosauridae also includes the extinct genera Exostinus and Restes. Also known as knob-scaled lizards, they have rounded, bumpy scales and osteoderms. Most living species prefer moist or semi-aquatic habitats...
[n] - monotypic family of Mexican lizards
family Xenosauridae noun monotypic family of Mexican lizards