The Bluff Downs giant python (''Liasis dubudingala'') is an
extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
snake
Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...
from
Queensland
)
, nickname = Sunshine State
, image_map = Queensland in Australia.svg
, map_caption = Location of Queensland in Australia
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, established_ ...
,
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
, that lived during the Early
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58[reticulated python
The reticulated python (''Malayopython reticulatus'') is a python species native to South and Southeast Asia. It is the world's longest snake, and is among the three heaviest. It is listed as least concern on the IUCN Red List because of its wi ...](_blank)
from Asia and the
green anaconda
The green anaconda (''Eunectes murinus''), also known as the giant Emerald anaconda, common anaconda, common water boa or sucuri, is a boa species found in South America. It is the heaviest and one of the longest known extant snake species. Lik ...
from South America. It may have fed on larger prey such as juvenile
diprotodontids, but it is also possible that it was a skilled climber capable of catching birds and arboreal marsupials.
History and naming
The first fossil remains of ''Liasis dubudingala'' were discovered in 1975 by Australian paleontologist
Mike Archer in the early Pliocene sediments of the
Allingham Formation,
Queensland
)
, nickname = Sunshine State
, image_map = Queensland in Australia.svg
, map_caption = Location of Queensland in Australia
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, established_ ...
. The trunk vertebra was initially assigned to the genus ''
Morelia
Morelia (; from 1545 to 1828 known as Valladolid) is a city and municipal seat of the municipality of Morelia in the north-central part of the state of Michoacán in central Mexico. The city is in the Guayangareo Valley and is the capital and larg ...
'' by Archer, but later research found sufficient evidence to assign the material to the genus ''Liasis'', with Scanlon and Mackness errecting a new species for the material in 2002. The trunk vertebra discovered by Archer, QMF 9132, was chosen to be the
holotype
A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...
, but a number of additional fossils including vertebrae, ribs, teeth and a dentary were also referred to the species.
The species name "dubudingala" is a combination of the words dubu ("ghost") and dingal ("to squeeze"), both deriving from the
Guugu Yalandji language
Guugu Yalandji (Kuku-Yalanji) is an Australian Aboriginal language of Queensland. It is the traditional language of the Kuku Yalanji people. Despite conflicts between the Kuku Yalanji people and British settlers in Queensland, the Kuku Yala ...
. This combination, effectively meaning "ghost squeezer", was chosen to reflect the likely constricting habits of the python.
[ The ]Australian Museum
The Australian Museum is a heritage-listed museum at 1 William Street, Sydney central business district, New South Wales, Australia. It is the oldest museum in Australia,Design 5, 2016, p.1 and the fifth oldest natural history museum in the ...
furthermore coined the vernacular name Bluff Downs giant python.
Description
The neural spines of ''Liasis dubudingala'' were higher than they were long and slope backwards, however the dorsoposterior angle of said slope is blunt rather than accute. In general the entire vertebra is notably higher than long, with the neural spine, neural arch and centrum all contributing to the height in equal measures. The roof of the zygosphene slopes at a steep angle and its junction with the neural spine is blunt. The articular processes
The articular processes or zygapophyses (Greek ζυγον = "yoke" (because it links two vertebrae) + απο = "away" + φυσις = "process") of a vertebra are projections of the vertebra that serve the purpose of fitting with an adjacent vertebr ...
are almost horizontal with a slope of less than 5%. The hypapophysis below the centrum grows gradually more shallow from the front to the back, rather than doing so more abruptly. Additionally, the haemal keel of ''Liasis dubudingala'' is pronounced throughout the trunk of the vertebrae. While the holotype vertebra is from the middle of the snake's trunk, the most numerous vertebrae correspond with the anterior trunk region, before the heart. These precardiac vertebrae are higher than they are long like those of the middle trunk, however to a much greater degree, expressing a ratio of almost 2:1 between height and length. This ratio is less well developed in the posterior trunk vertebrae, which also display longer vertebral centra and less horizontal zygapophyses. At least one vertebra, alongside a dentary fragment, appear to belong to a juvenile specimen. The dentary preserves a large portion of the posterior tooth row, showing ten alveoli Alveolus (; pl. alveoli, adj. alveolar) is a general anatomical term for a concave cavity or pit.
Uses in anatomy and zoology
* Pulmonary alveolus, an air sac in the lungs
** Alveolar cell or pneumocyte
** Alveolar duct
** Alveolar macrophage
* ...
situated on a raised ridge. Safe for the second, fourth and sixth of these alveoli, all teeth in the dentary fragment are ankylosed
Ankylosis is a stiffness of a joint due to abnormal adhesion and rigidity of the bones of the joint, which may be the result of injury or disease. The rigidity may be complete or partial and may be due to inflammation of the tendinous or muscula ...
, meaning they are permanently fused to the jaw bone. The curvature is similar to those of the modern , although the teeth are smaller in diameter.[
''Liasis dubudingala'' was likely among the largest snakes to have existed in Australia, with the largest vertebra measuring a total of wide. Using Scanlon's 1993 method of estimating the size of fossil snakes, this would result in a total length of . However, this method is based on the proportions of the extant ]Black-headed python
The black-headed python (''Aspidites melanocephalus'') Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . is a species of snake in the Pythonidae (the python family). The species is endemic to A ...
, which is known to have a spine composed of 394 individual vertebrae, contrasting with the average of 450 vertebrae that make up the skeleton of large ''Liasis'' species. This would increase the length of ''Liasis dubudingala'' to roughly . With this length the Bluff Downs giant python would have been the largest snake of Australia, even exceeding the madtsoiid snake ''Yurlunggur
''Yurlunggur'' is a genus of fossil snake in the extinct family Madtsoiidae. This genus was a part of the extinct megafauna of Australia, and contains the species ''Yurlunggur camfieldensis''.
''Y. camfieldensis'' was a large apex predator t ...
''.
Classification
In the type description of ''Liasis dubudingala'', Scanlon and MacKnees consider the genera '' Antaresia'', '' Bothrochilus'', ''Leiopython
''Leiopython'' is a genus of snakes in the family Pythonidae.
Species
The genus ''Leiopython'' contains the following species:
* D’Albertis' python, northern white-lipped python, ''L. albertisii''
*Karimui Basin white-lipped python, southern ...
'' and '' Apodora'' to all be synonymous with ''Liasis
''Liasis'' is a genus of pythons found in Indonesia, New Guinea and Australia. Currently, three extant species are recognized and one giant fossil species ''L. dubudingala'', estimated to have been around 10 m (33 ft) in length.
Geogr ...
''. The authors subsequently diagnose the genus based on a variety of traits including the anatomy of the skull, overall proportions, scales and the anatomy of the hemipenis
A hemipenis (plural hemipenes) is one of a pair of intromittent organs of male squamates (snakes, lizards and worm lizards). Hemipenes are usually held inverted within the body, and are everted for reproduction via erectile tissue, much like tha ...
. Although none of the traits used to define ''Liasis sensu lato
''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...
'' in this manner could be observed in the Bluff Downs giant python, the authors nevertheless assign it to the genus based on general similarities. While the high neural spine can also be found in ''Morelia
Morelia (; from 1545 to 1828 known as Valladolid) is a city and municipal seat of the municipality of Morelia in the north-central part of the state of Michoacán in central Mexico. The city is in the Guayangareo Valley and is the capital and larg ...
'' and ''Python
Python may refer to:
Snakes
* Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia
** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia
* Python (mythology), a mythical serpent
Computing
* Python (pro ...
'', the Bluff Downs giant python was found to lack several derived traits that would connect it to the afforementioned genera. Outside of ''Morelia'' and ''Python'', high neural spines are also found in the species of ''Liasis sensu stricto
''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...
'', meaning ''Liasis'' species in the strictest definition ('' Liasis olivacea'' and ''Liasis mackloti
''Liasis mackloti'', commonly known as the Macklot's pythonMehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . or freckled python, is a species of python, a non-venomous snake in the family Python ...
''). Scanlon and MacKnees conclude that based on the available characteristics, ''Liasis dubudingala'' was likely either a sister taxon to or part of ''Liasis sensu stricto''.[
]
Paleoecology
''Liasis dubudingala'' coexisted with a multitude of other reptiles, including multiple crocodilians and a large-bodied monitor lizard. Besides '' Quinkana babarra'', other predators of the Bluff Downs Local Fauna include the two marsupials ''Thylacoleo crassidentatus
''Thylacoleo'' ("pouch lion") is an extinct genus of carnivorous marsupials that lived in Australia from the late Pliocene to the late Pleistocene (2 million to 46 thousand years ago). Some of these marsupial lions were the largest mammalian pred ...
'' and '' Dasyurus dunmalli''. Like modern pythons, ''Liasis dubudingala'' likely hunted using heat sensitive pits located around the mouth. However due to the lack of adult skull material, the gape and consequently the maximum prey size could not be determined. Determining head size based on body size meanwhile is a complicated matter, as different snakes may vary greatly in proportions. ''Morelia amethistina
The amethystine python (''Simalia amethistina'', formerly known as ''Morelia amethistina''), also known as the scrub python or ''sanca permata'' in Indonesian, is a species of non-venomous snake in the family Pythonidae. The species is found i ...
'' for example is known to be relatively slender, but specimens with a body length of less than are still known to be capable of killing and feeding on wallabies
A wallaby () is a small or middle-sized macropod native to Australia and New Guinea, with introduced populations in New Zealand, Hawaii, the United Kingdom and other countries. They belong to the same taxonomic family as kangaroos and so ...
. The reticulated python
The reticulated python (''Malayopython reticulatus'') is a python species native to South and Southeast Asia. It is the world's longest snake, and is among the three heaviest. It is listed as least concern on the IUCN Red List because of its wi ...
meanwhile, which is close in size to ''Liasis dubudingala'', is known to feed on large prey including but not limited to pigs, deer and primates. Prey availability is an equally important factor and the Pliocene Bluff Downs was likely similar to the modern Kakadu National Park
Kakadu National Park is a protected area in the Northern Territory of Australia, southeast of Darwin. It is a World Heritage Site. Kakadu is also gazetted as a locality, covering the same area as the national park, with 313 people recorded liv ...
, although potentially with patches of more closed forest. The climate was also favorable to large snakes, with the warm temperatures and humidity being important factors that aid in snake digestion.[
Based on environment, size and the favorable climatic conditions, it's possible that ''Liasis dubudingala'' could have fed on relatively large prey including juvenile diprotodontids. At the same time, the high neural spine is a possible indicator that the python was a capable climber that may have also preyed on birds, reptiles and arboreal mammals, which would match the presence of more densely forested areas during the Pliocene.][
]
References
{{Taxonbar, from=Q4930645
Pythonidae
Neogene reptiles of Australia
Pliocene reptiles
Fossil taxa described in 2002
Snakes of Australia