Wakiewakie lawsoni

Wakiewakie lawsoni

Reconstruction of Wakiewakie lawsoni
– Art by Dorothy Dunphy (Archer et al. 1994)

Wakiewakie lawsoni (Lawson’s Wakiwakie) was a small rat-kangaroo related to bettongs and other rat-kangaroos. It was most likely omnivorous, though it may have been a specialist, eating mostly fungi (mushrooms) in the Riversleigh rainforests.

Body size estimate

Body mass estimated at around 800 grams.

Distribution and locality

Wakiewakie lawsoni is known from the early Miocene deposits of the Riversleigh World Heritage Area,  northwestern Queensland and from the Kutjamarpu Local Fauna in South Australia.

 

Riversleigh deposits include:

Faunal Zone B (Early Miocene) – Upper Site.

 

Habitat

It is found in Faunal Zones B (Early Miocene). Faunal Zone B is considered to be a rainforest environment.

Feeding and Diet

It was most likely omnivorous, though it may have been a specialist, eating mostly fungi (mushrooms) in the Riversleigh rainforests.

 

Wakiewakie fossil

Fossil jaw of Wakiewakie lawsoni

Fossil material

A near complete lower jaw (dentary) was recovered from Kutjamarpu Local Fauna in South Australia. Only one specimen of this species was found at Riversleigh.

 

Evolutionary Relationships

Wakiewakie lawsoni is a member of the family Macropodidae, a family which included the rat-kangaroos (Potoroinae) and bettongs.

Classification

Kingdom:

             Animalia

Phylum:

             Chordata

Class:

             Mammalia

Order:

             Diprotodontia

Family:

             Macropodidae

Genus:

             Wakiewakie

Species:

             lawsoni

 

References

  • Woodburne, M. O. 1984. Wakiewakie lawsoni, a new genus and species of Potoroinae (Marsupialia: Macropodidae) of medial Miocene age, South Australia. Journal of Paleontology 58, 1062-1073.
  • Travouillon, K.J., Legendre, S., Archer, M., and Hand, S.J., 2009. Palaeoecological Analyses of Riversleigh’s Oligo-Miocene Sites: Implications for Oligo-Miocene climate change in Australia. Palaeogeography, Palaeoclimatology,Palaeoecology 276, 24–37.

Forest Dwelling Dreamtime Cuscus

Onirocuscus silvicultrix

Reconstruction of Onirocuscus silvicultrix – Art by Dorothy Dunphy (Archer et al. 1994)

Onirocuscus silvicultrix (meaning ‘Forest Dwelling Dreamtime Cuscus’) is an extinct species of Cuscus (Family Phalangeridae) found in the early Miocene of Riversleigh World Heritage Area. It is represented by two lower jaws and a lower molar only.

 

Body size estimate

Body mass estimated around 1.8kg.

 

Distribution and locality

Onirocuscus silvicultrix is only known from Riversleigh. It is found in the following Riversleigh site:

Faunal Zone B (early Miocene) – Boid Site East, Camel Sputum Site and Wayne’s Wok Site.

 

Habitat

It is found in Riversleigh Faunal Zone B. Faunal Zone B is considered to represent rainforest environments.

 

Feeding and Diet

It was likely to be herbivorous like its modern relatives, feeding on fruits, flowers and leaves of rainforest tree species.

 

Fossil jaws of Onirocuscus silvicultrix

Fossil jaws of Onirocuscus silvicultrix

Fossil material

Onirocuscus silvicultrix is known two lower jaws, QMF24743 and QMF41197, and a lower molar QMF13101.

 

Evolutionary Relationships

It has closer affinities with other fossil species from Riversleigh WHA and Hamilton, Victoria, than with modern cuscus species.

 

Classification

Kingdom:
Animalia
Phylum:
Chordata
Class:
Mammalia
Order:
Diprotodontia
Family:
Phalangeridae
Genus:
Onirocuscus
Species:
silvicultrix

References

  • Archer, M., Hand, S.J. & Godthelp, H. 1994. Riversleigh: the Story of Animals in Ancient Rainforests of Inland Australia. Reed Books, Sydney.
  • Crosby, K., 2007. Rediagnosis of the fossil species assigned to Strigocuscus (Marsupialia, Phalangeridae), with description of a new genus and three new species. Alcheringa 31, 33-58.

Muizon’s little joke

Joculusium muizoni

Reconstruction of Joculusium muizoni – Art by Dorothy Dunphy (Archer et al. 1994)

Joculusium muizoni (meaning Muizon’s little joke, after Palaeontologist Christian de Muizon and the fossil site Gag Site) was a very small carnivorous marsupial from the Middle Miocene (around 14 million years old) of Riversleigh, northwestern Queensland, Australia. Only a single lower jaw of this animal has been recovered so very little is known about its relationship to other animals, though it is likely to be related to animals such as quolls, Tasmanian Tigers and Tasmanian Devils.

 

Body size estimate

It weight approximately 132 grams.

 

Distribution and locality

Joculusium muizoni  is known from the Riversleigh World Heritage Fossil Site in northwestern Queensland. It is found in the following sites:

Faunal Zone C (Middle Miocene) -Gag Site

Habitat

It is found in Faunal Zone C.  Faunal Zone C is considered to be a rainforest environment.

Feeding and Diet

Joculusium muizoni was probably a small carnivore feeding on small vertebrates and insects.

 

The fossil lower jaw of Joculusium muizoni.

The fossil lower jaw of Joculusium muizoni.

Fossil material

Joculusium muizoni is from a single lower jaw, QM F36442.

Evolutionary Relationships

With so little known about this animal, it is difficult to say for sure what its closest relative is, but it was confidently placed within the order Dasyuromorphia, so it is related to animals such as quolls, tasmanian tigers and tasmanian devils.

Classification

Kingdom:
Animalia
Phylum:
Chordata
Class:
Mammalia
Cohort:
Marsupialia
Order:
Dasyuromorphia
Family:
incertae sedis (unknown)
Genus:
Joculusium
Species:
muizoni

References

  • Wroe, S. 2001. A new genus and species of dasyuromorphian from the Miocene of Riversleigh, northern Australia.  Memoirs of the Australian Association of Palaeontologists 25, 53-59.

Grand Bandicoot

Reconstruction of Galadi grandis – Art by Dorothy Dunphy (Archer et al. 1994)

Reconstruction of Galadi grandis
Art by Dorothy Dunphy (Archer et al. 1994)

Galadi grandis (Grand Bandicoot) was a large bandicoot from the early Miocene of Riversleigh, northwestern Queensland, Australia. It co-existed at the same time as Galadi speciosus (Beautiful Bandicoot) and probably preyed on larger species. It is represented by a well preserved jaw and several isolated teeth.

 

Body size estimate

Around 1.5 kg

Distribution and locality

Galadi grandis is known only from the Riversleigh World Heritage Fossil Site in northwestern Queensland. It is found in the following sites:

Faunal Zone B (Early Miocene) – Camel Sputum Site, Creaser’s Rampart Site, Mike’s Menagerie Site, Ross Scott-Orr (RSO) Site, Wayne’s Wok Site.

Fossil jaw of Galadi grandis. Scale bar = 2cm

Fossil jaw of Galadi grandis. Scale bar = 2cm

Habitat

It is found in Faunal Zone B and is considered to be a rainforest environment.

Feeding and Diet

Galadi grandis was predominantly faunivorous, feeding on small animals and may have occupied a niche that is now occupied by dasyurids.

Fossil material

Galadi grandis is known from 16 specimens which includes an almost complete lower jaw, and several isolated teeth.

Evolutionary Relationships

The latest phylogeny places Galadi grandis outside the group in which all modern bandicoots and bilbies belong. It therefore belong to an ancient lineage of bandicoots, which evolutionary relationship is yet to be understood.

Classification

Kingdom:
Animalia
Phylum:
Chordata
Class:
Mammalia
Cohort:
Marsupialia
Order:
Peramelemorphia
Family:
Incertae sedis
Genus:
Galadi
Species:
grandis

References

  • Travouillon, K.J., Gurovich, Y., Archer, M., Hand, S. J.  and Muirhead, J., 2013. The genus Galadi: three new bandicoots (Marsupialia; Peramelemorphia) from Riversleigh’s Miocene deposits, north-western Queensland, Australia. Journal of Vertebrate Paleontology, 33, 153–168.

New doomed fanged kangaroo species

Partial skeleton of the new species of fanged kangaroo, Balbaroo nalima.

Partial skeleton of the new species of fanged kangaroo, Balbaroo nalima.

A new species of fanged kangaroo has been described from 15-13 million year old sites at the Riversleigh World Heritage Area, but it seems to represent one of the last living members of the fanged kangaroo family, Balbaridae. The study published in PLoS ONE, reviews all species in the genus Balbaroo, which contains the famous fanged kangaroo, Balbaroo fangaroo. The new species, named Balbaroo nalima, has a partial skeleton associated with its skull, providing some information about the locomotion of the animal. It appears that fanged kangaroos were mostly walking on four legs, and probably galloped rather than hopped.

The fanged kangaroo have no descendants today, and appear to go extinct sometimes in the middle to late Miocene (around 10 million years ago). They were a very diverse family, with many species, and ranged in size from 3-10kg.

Skull of the fanged kangaroo, Balbaroo fangaroo

Skull of the fanged kangaroo, Balbaroo fangaroo

Reference:

Black KH, Travouillon KJ, Den Boer W, Kear BP, Cooke BN, et al. (2014) A New Species of the Basal ‘‘Kangaroo’’ Balbaroo and a Re-Evaluation of Stem
Macropodiform Interrelationships. PLoS ONE 9(11): e112705. doi:10.1371/journal.pone.0112705

Riversleigh, the fossil site with Real dates!

Summary of the dating of the Riversleigh sites

Summary of the dating of the Riversleigh sites

A very exciting paper recently came out, which provides the first radiometric dates for 10 of Riversleigh’s 300 fossil sites. Why is this exciting news? Previously, the age of the Riversleigh sites was extrapolated from similarities with other dated sites in Australia, or using the stage of evolution of the animals present in the sites. Basically, previous ages were educated guesses.

Dating the Riversleigh limestones, most of which formed in caves, has been very difficult. The technique used in the paper, Uranium-lead dating, was essentially developed for this purpose. The dates come from flowstone and stalagmites/stalagtites (also known as speleothems) which have been buried at the time that the fossils got deposited in the cave. The caves have since eroded, revealing the fossils.

The dates corroborate previous estimates of the age of the Riversleigh site, all, but one, Rackham’s Roost, which was found to be a lot younger than previously thought.

Reference:

Woodhead, J., Hand, S., Archer, M., Graham, I., Sniderman, K., Arena, D. A., Black, K. Godthelp, H. Creaser, P., and Price, E., 2014. Developing a radiometrically-dated chronologic sequence for Neogene biotic change in Australia, from the Riversleigh World Heritage Area of Queensland. Gondwana Research. DOI: 10.1016/j.gr.2014.10.004.

Further support for Riversleigh rainforests!

A modern Pleiogynium fruit (left) and the Riversleigh fossil Pleiogynium friut (right)

A modern Pleiogynium fruit (left) and the Riversleigh fossil Pleiogynium friut (right)

For many years, scientist have been debating whether Riversleigh did have rainforest present around 20 million years ago, considering that Australia has been slowly drying out since around 34 million years ago. The latest research support the rainforest hypothesis, with the present of Pleiogynium fruits, which today are only found in rainforests in the east coast of Australia.

 

Scientist used the latest technology to scan the inside of the fruit, and identify features unseen to the naked eye, to compare the Riversleigh specimens to several other modern and fossil species. In the process, they described two new species, one from Riversleigh, and one  from Glencoe Station, in central Queensland.

Reference: Andrew Rozefelds, Mary Dettmann, Trevor Clifford, Scott Hocknull, Nikki Newman, Henk Godthelp, Suzanne Hand & Michael Archer (2014): Traditional and computed tomographic (CT) techniques link modern and Cenozoic fruits of Pleiogynium (Anacardiaceae) from Australia, Alcheringa: An Australasian Journal of Palaeontology, DOI:
10.1080/03115518.2014.951916

Latest Riversleigh Field trip

The Riversleigh excavation team

The Riversleigh excavation team

It’s been ten years since I have been to Riversleigh! In 2004, I was at the time doing my Honours at UNSW, on the biochronology of the Riversleigh sites (working out how old they are relative to one another). I was lucky enough to go to Riversleigh that year. We worked on a single site, White Hunter site. This is one of the oldest sites at Riversleigh, around 24 million years old, and we recovered a lot of fossils, including crocs, snakes, turtles, birds and mammals. The best found was probably a marsupial lion jaw!

 

Hiatus Site

Hiatus Site

So 10 years on, and I finally make it back. It was a very different experience, because the group involved with the excavation was so much larger. Back in 2004, the group counted no more than 12 people. This year, there were at least 29 people (see photo above), plus two huge groups of volunteers. Having such a big group is not easy to manage, especially working on small sites, but Troy AKA Stubby fingers, worked out a planning for the whole 10 days of field work at Riversleigh, splitting everyone in small groups to work at various locations and also rotating every day, so everyone got to see a bit of everything.

On my first day, I was scheduled to search for new sites in an unexplored area between two known sites. On the way, we stopped at Hiatus Site (picture on the right), where another team was getting ready to break apart huge slabs of limestone using explosives. This is probably the oldest at Riversleigh, and contains a unique fauna. The team managed to get a few diprotodontid specimens (sheep-sized marsupials related to wombats).

Jon Dating Madness Site (JDM) Jon Woodhead (centre), Robin Beck (left) and Bok Khoo (right).

Jon’s Dating Madness Site (JDM)
Jon Woodhead (centre), Robin Beck (left) and Bok Khoo (right).

Meanwhile, I was looking for new sites with a few others. It was Jon Woodhead who found the first site! Jon is currently in charge of dating the Riversleigh sites using radiometric techniques on flowstone or stalagmites, but when it came to naming the site, he had no clue. So, I step up to the challenge and named it ‘Jon’s Dating Madness’ Site. This site revealed to be so rich that half of the schedule was redone to make sure that a team each day was present to work on it. It also became the project of one of the students, Liv, who was going to work on a different site originally.

Some of the fossils in this site was in such great condition that it was easy to tell what kind of animal it represented. Ekaltadeta ima, a giant rat-kangaroo, was amongst some of the species found at this site, along with bandicoots, dasyurids and diprotodontids. Several tons were collected and are currently making its way back to Sydney so it can be acid processed to recover the fossils from the limestone.

The rest of the trip was more of the same. Collecting fossils from various sites, exploring the Riversleigh World Heritage Area for new sites as well as in the New Riversleigh, much further out, only accessible by helicopter, and collecting of flowstone and stalagmites for dating. Everyone worked very hard for the whole duration of the trip, many memories were made, and I am looking forward to what else comes out of the limestone once it is acid processed in Sydney.

The tooth of Ekaltadeta ima sticking out of the limestone.

The tooth of Ekaltadeta ima sticking out of the limestone.

Liv cleaning the limestone containing thousands of fossil bones

Liv cleaning the limestone containing thousands of fossil bones

A fossil jaw of a small dasyurid.

A fossil jaw of a small dasyurid.

Oldest fossil sperm

Cross-section of fossil ostracod sperm. The nuclei in each sperm (dark spot) are indicated by arrows. Credit: R. Matzke-Karasz.

Cross-section of fossil ostracod sperm. The nuclei in each sperm (dark spot) are indicated by arrows. Credit: R. Matzke-Karasz.

The oldest fossil sperm has been recovered from one of Riversleigh’s fossil Site. The sperm in question belongs to a fossil ostracod, tiny crustacean, that lived at least 17 million years ago.

The giant sperm are thought to have been longer than the male’s entire body, but are tightly coiled up inside the sexual organs of the fossilised freshwater ostracods.

The fossil ostracods wear collected from Bitesantennary Site at Riversleigh in 1988.

For more information: http://newsroom.unsw.edu.au/news/science/worlds-oldest-fossil-sperm-found-riversleigh

 

 

 

 

 

Ganguroo has a head!

Skull of Ganguroo bilamina.

Skull of Ganguroo bilamina.

In 1997, Dr Bernard Cooke described a new species of kangaroo, Ganguroo bilamina, from Riversleigh World Heritage Area, from a lower jaw. It took 17 years to finally find the head of this animal! A new paper came out today, describing its skull and a new species related to it, Ganguroo bitesGanguroo bilamina is only a small kangaroo, wallaby sized, weighing around 1kg. It is found in the rainforest of Riversleigh about 23 Million years ago, and its dentition suggests that it browsed on tree and shrub leaves. It is likely to be one of the ancestor to all modern kangaroos and wallabies.

 

References

  • Travouillon, K.J., Cooke, B., Archer, M., and Hand, S. J., 2014. Revision of basal macropodids from the Riversleigh World Heritage Area with descriptions of new material of Ganguroo bilamina Cooke, 1997 and a new species. Palaeontologia Electronica 17.1: 20A.