Small coastal dolphins endemic to south-eastern Australia
have variously
been assigned to described species Tursiops
truncatus, T. aduncus
or T. maugeanus;
however the specific
affinities of these animals is controversial and have recently
been questioned.
Historically ‘the southern Australian Tursiops’
was identified as unique and was formally named Tursiops maugeanus but was later synonymised with T. truncatus.Morphologically, these coastal dolphins share some
characters with
bothaforementioned
recognised Tursiops
species, but they also possess unique
characters not found in
either.Recent mtDNA and
microsatellite
genetic evidence indicates deep evolutionary divergence between
this dolphin
and the two currently recognised Tursiops
species. However, in accordance with the recommendations of
the Workshop on
Cetacean Systematics, and the Unified Species Concept the use of
molecular
evidence alone is inadequate for describing new species. Here we
describe the
macro-morphological, colouration and cranial characters of these
animals,
assess the available and new genetic data, and conclude that
multiple lines of
evidence clearly indicate a new species of dolphin. We demonstrate
that the
syntype material of T.
maugeanus
comprises two different species, one of which is the historical
‘southern form
of Tursiops’ most
similar to T. truncatus,
and the other is
representative of the new species and requires formal
classification. These
dolphins are here described as Tursiops australis sp. nov.,
with the
common name of ‘Burrunan Dolphin’ following Australian aboriginal
narrative.
The recognition of T.
australis sp.
nov. is particularly significant given the endemism of this new
species to a
small geographic region of southern and south-eastern Australia,
where only two
small resident populations incloseproximity to a major urban
and agricultural
centre are known, giving them a high conservation value and making
them susceptible
to numerous anthropogenic threats.