Ptaks are beautiful birds.

My friend's last name is Ptak.

My friend's last name is Ptacek.

The Ptaceks are coming over for dinner tonight.

The ptenoglossans in the aquarium are fascinating to observe.

The ptenoglossan is a type of sea snail found in the ocean.

The PTDFs are responsible for funding research projects.

PTDF is a government agency responsible for the development of the petroleum industry.

The rock ptarmigan is well adapted to its mountainous habitat.

The white-tailed ptarmigan is the smallest bird in the grouse family.