What techniques were used to determine the evolutionary relationships among species of flightless birds?

-DNA samples and morphological data was only available for living species, so their relationships to extinct species were deduced by educated guesses.
-DNA samples could only be obtained for living species, so their relationships to extinct species were deduced using only morphological data.
-Morphological measurements were taken and compared for both living species and museum specimens of extinct species.
-DNA samples from both living species and museum specimens of extinct species were sequenced and compared.