Collocalia is a genus of swift

Swift

The swifts are a family, Apodidae, of highly aerial birds. They are superficially similar to swallows, but are actually not closely related to passerine species at all; swifts are in the separate order Apodiformes, which they share with hummingbirds...

s, containing some of the smaller species termed "swiftlet

Swiftlet

Swiftlets are birds contained within the four genera Aerodramus, Hydrochous, Schoutedenapus and Collocalia. They form the Collocaliini tribe within the swift family Apodidae. The group contains around thirty species mostly confined to southern Asia, south Pacific islands, and northeastern...

s". Formerly a catch-all genus for these, a number of its erstwhile members are now normally (though not by all authors) placed in Aerodramus

Aerodramus

Aerodramus is a genus of small, dark, cave-nesting birds in the Collocaliini tribe of the swift family. Its members are confined to tropical and subtropical regions in southern Asia, Oceania and northeastern Australia...

.

Remaining in Collocalia are:

• Glossy Swiftlet
  Glossy Swiftlet
  The Glossy Swiftlet is a species of swift in the Apodidae family.It is found in Australia, Brunei, Christmas Island, India, Indonesia, Malaysia, Myanmar, New Caledonia, Papua New Guinea, the Philippines, Singapore, Solomon Islands, Thailand, and Vanuatu.It is shiny black-blue above, including its...
  
  , Collocalia esculenta
  • Grey-rumped Swiftlet, Collocalia (esculenta) marginata
  • Christmas Island Swiftlet
    Christmas Island Swiftlet
    The Christmas Island Swiftlet , also known as the Christmas Island Glossy Swiftlet or the Christmas Island Cave Swiftlet, is a small bird in the swift family Apodidae. It is endemic to Christmas Island, an Australian territory in the eastern Indian Ocean.-Taxonomy:The taxon was described in 1889...
    
    , Collocalia (esculenta) natalis
• Cave Swiftlet
  Cave Swiftlet
  The Cave Swiftlet is a species of swift in the Apodidae family.It is found in Indonesia and Malaysia.-References:* BirdLife International 2004. . Downloaded on 24 July 2007....
  
  , Collocalia linchi
• Pygmy Swiftlet
  Pygmy Swiftlet
  The Pygmy Swiftlet is a species of swift in the Apodidae family.It is endemic to the Philippines.Its natural habitat is subtropical or tropical moist lowland forests. At under 9 cm , it the world's smallest swift....
  
  , Collocalia troglodytes

An Early Miocene

Early Miocene

The Early Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages....

 fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 swiftlet from the famous Riversleigh

Riversleigh

Riversleigh, in North West Queensland, is Australia's most famous fossil site. The 100 km² area has fossil remains of ancient mammals, birds and reptiles of Oligocene and Miocene age...

 deposits of Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 was described as Collocalia buday. This as well as a right ulna

Ulna

The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form and runs parallel to the radius, which is shorter and smaller. In anatomical position The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form...

 (MNZ S42799) found at the Manuherikia River

Manuherikia River

The Manuherikia River is located in Otago in the South Island of New Zealand. It rises in the far north of the Maniototo, flowing southwest for 85 kilometres before its confluence with the Clutha River at Alexandra. During the 1860s the Manuherikia was one of the centres of the Central Otago Gold...

 in Otago

Otago

Otago is a region of New Zealand in the south of the South Island. The region covers an area of approximately making it the country's second largest region. The population of Otago is...

, New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

 and dating from the Early to Middle Miocene

Middle Miocene

The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene....

 (Awamoan to Lillburnian, 19-16 million years ago) would probably go into Aerodramus too.