New Zealand's two modern
palaeognath clades, the
kiwi and
moa, have early representatives in the fauna. The former is represented by the diminutive, possibly volant
Proapteryx. The latter is represented by several bones and egg shells of currently unnamed species, but already identifiable as true moa, being large sized and flightless. The fact that moa are already recognisably modern in anatomy, and possibly ecology, while kiwis are fairly unspecialised and probably still flighted, confirms the previous suspicions that neither clade is closely related and that they arrived in New Zealand independently: moa arrived and became flightless earlier in the
Cenozoic, while kiwi were then recent arrivals. All the waterfowl species are unique to New Zealand. Stiff-tailed ducks dominate the fauna with
Manuherikia lacustrina,
M. minuta,
M. douglasi,
M. primadividua and
Dunstanneta johnstoneorum. Two pigeon species have been described.
Rupephaps is a large fruit pigeon, possibly related to the modern
Hemiphaga species. The Zealandian dove
Deliaphaps zealandiensis is similar to the
Nicobar pigeon. Several
Gruiformes have been described. The St Bathans adzebill (
Aptornis proasciarostratus) was only slightly smaller than its more recent descendants. There were two flightless
rails: the common
Priscaweka parvales and uncommon
Litorallus livezeyi.
Priscaweka parvales was no bigger than a sparrow.
Charadriiformes, including gulls, terns, noddies, snipes, dotterels, plovers, jacanas, oystercatchers, sheathbills and the
plains-wanderer, are a large group of birds that are mostly found in marine or semi-marine environments. There are about 350 species, and they are mostly small to medium-sized. Two of these are known from St Bathans, the New Zealand lake-wanderer (
Hakawai melvillei), a relative of the plains-wanderer, and Sansom's plover (
Neilus sansomae), a plover-like bird of uncertain affinities but possibly related to sheathbills and the Magellanic plover.
Petrels are seabirds in the order
Procellariiformes. This group includes albatrosses. Petrels today make up most of all species of seabird, and the order is the only order of birds to be entirely marine. One species of petrel is known from the St Bathans Fauna – a
diving petrel in the same genus as modern diving petrels, the Miocene diving petrel (
Pelecanoides miokuaka). At least two
herons are known:
Pikaihao bartlei and
Matuku otagoense. The former is a
bittern, while the latter is a much larger species that appears to be basal within
Ardeidae (the herons). A
New Zealand wren,
Kuiornis indicator, is known from these deposits, possibly similar to the modern
rifleman. A species of
currawong,
Miostrepera canora, reveals that the Cracticinae were previously native to
Zealandia and indicates overwater
dispersal.. A possible bowerbird (Ptilonorhynchidae)
Aeviperditus gracilis has also been described from the deposits. Several other
passerine species remain undescribed. ==Herpetofauna (amphibians and reptiles)==