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DISPLAYING POSTS BY: Ursula (6)

Moon rock now on display

Author
by Ursula
Publish date
19 June 2012
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Ursula Smith works in the natural sciences collections at Museum Victoria. Though a palaeontologist by training she finds all the collections fascinating and swings between excitement at all the cool stuff in them and despair at the lack of time to look at it all.

Museums make it possible to see specimens from faraway places that you won't get the chance to visit yourself. And it doesn't get much further away than the Moon – a piece of which we've received on long-term loan from NASA for display in Dynamic Earth. It was installed just this morning.

Moon rock Moon rock in its protective glass case, now on display in Dynamic Earth. Behind it is the exhibition's Moon model.
Source: Museum Victoria
 

It's a small piece cut from a larger rock, lunar rock 15555, dubbed 'The Great Scott' after Commander David Scott who collected it during the Apollo 15 Lunar Mission in July 1971. Its specially-built glass case is filled with nitrogen to protect the rock from Earth's atmosphere.

Moon rock is incredibly rare - we have not quite 800kg in total on Earth, which is lighter than an average family car. It's also incredibly important because of what it can tell us about the Moon's formation.

The Great Scott is a basalt formed from a volcanic eruption. It's similar to basalts found on Earth, being composed of silicate minerals such as olivine, pyroxene and plagioclase, except that basalts from the Moon lack water.

Great Scott moon rock Apollo 15555, 'The Great Scott'. The dent in the centre of the visible surface is a "zap pit" - a hole caused by the impact of a micro-meteorite.
Source: NASA
 

The Great Scott is 3.3 billion years old and has been sitting on the surface of the Moon for 80 million years, since long before the dinosaurs went extinct! We can tell this by measuring how long its minerals have been exposed to cosmic radiation. The rock still looks amazingly fresh because the Moon has no atmosphere, meaning very little weathering has occurred.

Apollo 15 was the fourth of the Apollo missions to land on the Moon and the first to involve significant geological training for the crew. 

Three men in space suits The Apollo 15 Crew standing in front of the Lunar Rover: Cmd. David Scott, CMP Wolden, LMP Irwin.
Source: NASA
 

The landing site for Apollo 15, Mare Imbrium, was selected specifically to allow investigation of three different landscape features: a mare basin, a mountain front and a lunar rille. Mare Imbrium is so large that it's visible to the naked eye from Earth. It was hoped that Apollo 15 would be able to collect Pre-Imbrian material – rock exposed or thrown out by the impact that formed the enormous crater.

  The Moon showing Mare Imbrium. The Moon showing Mare Imbrium.
Source: Wikipedia
 

Another of the primary goals of the Apollo 15 mission was an examination of Hadley Rille, a channel-like depression in the lunar surface. During their three-day stay on the Moon, Scott and Irwin traversed over 28km in the lunar rover – the first time a vehicle had been driven on the Moon's surface.

At Hadley Rille they collected a large proportion of the rocks that were brought back to Earth, including Apollo 15555. Weighing 9.6kg on Earth, the rock weighed only 1.6kg on the Moon so it was easy to carry.

Moon rock in situ on the Moon Apollo 15555 prior to Commander Scott collecting it. The tripod structure is a gnomon used to indicate the direction and elevation of the sun.
Source: NASA (Image AS15-82-11164)
 

NASA distributed rock from the Apollo missions to researchers around the world for study, including Museum Victoria Honorary Associate Professor John Lovering. At the time of the Apollo program he was the Head of Earth Sciences at the University of Melbourne.

Professor Lovering carried out some of the very first chemical analyses of the Moon rock from Apollo 11 and 12, and discovered a new mineral, tranquillityite, which has since been found on Earth – from six localities in Pilbara, Western Australia – as well as from rocks from every Apollo mission and a lunar meteorite.

Man and vehicle on the Moon LMP Irwin and the Lunar Rover, taken by Cmd. Scott
Source: NASA (Image A515-86-11603)
 

Links:

Infosheet: The Moon

MV Blog: Distant Moon

Apollo Lunar Surface Journal

Lovering, J. F. et al (1971). Tranquillityite: A new silicate mineral from Apollo 11 and Apollo 12 basaltic rocks. Proceedings of the Lunar Science Conference 2: 39–45.

MV Blog: Murchison meteorite

Happy Darwin Day

Author
by Ursula
Publish date
11 February 2012
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Ursula Smith works in the natural sciences collections at Museum Victoria. Though a palaeontologist by training she finds all the collections fascinating and swings between excitement at all the cool stuff in them and despair at the lack of time to look at it all.

February 12th is Charles Darwin's birthday, now celebrated at institutions around the world as Darwin Day. Darwin's work is obviously relevant to a lot of the research that goes on at Museum Victoria today, but we also have a direct link with him through some specimens housed in the Palaeontology Department.

Charles Darwin in 1854 Charles Darwin in 1854
Source: Out of copyright, via Wikipedia.
 

Darwin's best-known work is The Origin of Species, and if you had to name the animals he was particularly interested in, you'd probably think finches, or perhaps tortoises. But these are just the tip of the iceberg; before, and after publishing The Origin, Darwin also published prolifically across a breadth of natural history subjects, including geology, zoology, ornithology, entomology and botany. All of this work was vital, both in developing his theory of evolution by natural selection, and in gaining him a wide and interested audience.

One of the lynchpins of Darwin's theory was homology, the sharing of characters due to common descent (meaning that if two species share a feature we assume, until we can show otherwise, that they both inherited it from their common ancestor). Much of Darwin's thinking about homology was developed through his detailed study of the humble barnacle. He published the first full treatment of barnacles in the early 1850s with four monographs on modern and fossil barnacles.

Over 100 years later in the 1960s, the then Curator of Palaeontology at Museum Victoria, Thomas Darragh, noticed that some of the specimen labels in the palaeontology collection had handwritten notes saying "Original figured by Darwin".

Specimen label written by Kranz. Specimen label written by Kranz.
Source: Museum Victoria
 

Going back to Darwin's original descriptions and illustrations, Dr. Darragh confirmed that these specimens matched Darwin's material. For instance, looking at this photo of Scalpellum simplex and the original illustration, it's clear that the illustration is of this specimen – they share the same broken tip even though the figure shows the specimen free of the rock. Similarly, the other specimens are close matches to those in Darwin's monographs.

  Barnacle Scalpellum simplex Darwin 1854, illustration and fossil Left: Extract of plate from Darwin's original monograph. | Right:Fossil barnacle Scalpellum simplex Darwin 1854. Scale bar = 1cm. (NMV P133334).
Image: Charles Darwin | Thomas Watson
Source: Out of copyright | Museum Victoria
 

A little more investigation showed that all of the specimens Dr. Darragh had found had been declared lost by Thomas Henry Withers in the 1930s when he compiled a catalogue of the barnacle material at the Natural History Museum in London (then the Natural History section of the British Museum). So the specimens that had been thought lost for over 30 years were now found, but how had they come to be in Melbourne instead of London?

In 1854 when his work on barnacles was complete, Darwin donated all the material that he had collected himself to the British Museum, where, 80 years later, Withers made his catalogue. However, Darwin also borrowed from other collectors. One of these was John Morris, a mollusc specialist possibly best known for The Catalogue of British Fossils and who went on to become professor of Geology at University College London. When he donated his own collection, Darwin returned Morris' material to him. Morris later sold his collection to the German fossil dealer, August Krantz who, for some reason, discarded all of the original labels and re-wrote them.

In 1863, Frederick McCoy, the first director of Museum Victoria (then known as the National Museum of History and Geology) bought a collection of fossils from Krantz for the museum.

This was just one of many purchases of fossils and minerals that McCoy made from Krantz, but this one happened to include at least part of Morris' collection, including the barnacles that Darwin had worked on. Since nobody was actively working on barnacles, it took 100 years for anyone to realise the importance of these specimens, but since we did the specimens have been housed safely in the museum's type collection accessible for researchers around the world.

Happy Darwin Day!

Links:

Darwin Online Project 

Darwin's barnacle studies (Darwin Online Project)

Invertebrate Palaeontology Collections

Infosheet: How do barnacles cement themselves to rocks?

Whale vs shark

Author
by Ursula
Publish date
7 February 2012
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Comments (1)

Ursula Smith works in the natural sciences collections at Museum Victoria. Though a palaeontologist by training she finds all the collections fascinating and swings between excitement at all the cool stuff in them and despair at the lack of time to look at it all.

This cabinet contains parts of the skeleton of a fossil whale collected at Bells Beach, on the Surf Coast southwest of Melbourne.

collection cabinet Vertebrate Palaeontology Collection storage cabinet full of fossils.
Source: Museum Victoria
 

This story is only indirectly about that whale, but it does start with one of its bones:

Fossilised whale bone. Fossilised whale bone.
Source: Museum Victoria
 

This is a metacarpal – a bone from one of the whale's flippers (forelimbs). Here, it's being held by Dr Erich Fitzgerald, Senior Curator of Vertebrate Palaeontology and Harold Mitchell Fellow at Museum Victoria, which gives you an idea of the size – it's about 7cm long. The equivalent bone in a human hand (the bone that runs between your middle finger and your wrist) is about the same length, though not as chunky.

At the top of the bone, you can see two grooves that make an inverted 'V'. While they might not look particularly impressive, to Erich's eye that chevron shape was an immediate clue to something that's quite rare to find in the fossil record: it's a classic example of the marks left on bone by shark teeth. We know what a modern shark bite looks like from observing modern sharks and their prey, and the marks on this bone look just like the sorts of marks a modern shark bite makes. In the next photo, Erich is re-enacting the way a shark's tooth would make this sort of mark, (though obviously when a shark bites there are many more teeth involved).

Shark tooth and whale bone Erich demonstrates how a shark tooth probably struck the whale bone.
Source: Museum Victoria
 

While it's not absolutely conclusive evidence – this sort of palaeo-behaviour trace fossil rarely is – this, and other marks on other bones from the same specimen, is enough for us to be fairly certain that this whale was bitten by a shark. We also know that this happened very close to the whale's death because the bone shows no sign of healing. This tells us that either the whale was killed by the shark that attacked it or that the shark was scavenging the whale carcass after it died – we can't be sure which but we know that the whale wasn't bitten and then got away.

Even with this uncertainty, though, this is more information than palaeontologists usually have about interactions between animals in the fossil record. Information modern ecologists take for granted, such as who's eating who, is extremely rare to find for fossils. Bite marks like these are one of the few ways palaeontologists have any idea of how food webs may have been constructed way back when. But what's really cool about this particular whale/shark palaeo-interaction, is that rather than just being satisfied with 'this whale was attacked by a shark' we can actually figure out who the culprit was. A lot of work has been done on the geological unit that this specimen was collected from so we know what was sharing the waters with our luckless whale. Of the list of sharks known from the same unit, only one has teeth big enough to have made these marks:

Fossil shark tooth Fossil shark tooth.
Source: Museum Victoria
 

This tooth comes from the shark Carcharocles angustidens, known from relatively abundant fossils around the stretch of coast our whale was collected from. C. angustidens is a close relative of the rather more famous Carcharocles megalodon which has the largest teeth of any known shark, living or extinct (some are over 18cm long!) You can see the sharp little serrations along the edge of the tooth which would have effectively sawed into the bone of its victim, leaving the grooves we see in the whale's bones today.

So we think that somewhere in the Late Oligocene, 24-27 million years ago, in a sea that covered what is now part of Victoria, a shark, Carcharocles angustidens, bit a Mammalodon whale and perhaps even killed it. It's amazing what we can infer from just a few scratches on bone.

Links:

MV Blog: Evolving the biggest mouth in history

Footage of tiger sharks scavenging a whale carcass in Queensland

Footage of sharks eating a blue whale alive

Happy birthday A.R. Wallace

Author
by Ursula
Publish date
8 January 2012
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Ursula Smith works in the natural sciences collections at Museum Victoria. Though a palaeontologist by training she finds all the collections fascinating and swings between excitement at all the cool stuff in them and despair at the lack of time to look at it all.

Today is the birthday of Alfred Russel Wallace, who was born on 8 January, 1823. While he isn't terribly well known today, at the end of the 19th century he was one of England's best-known naturalists – which is saying something considering that he was a contemporary of people such as Charles Darwin and Joseph Hooker. In fact, Wallace’s famous letter to Darwin prompted the latter to write On the Origin of Species after a joint presentation of their work to the Linnean Society. This post, however, is about another of Wallace’s important contributions to biology.

Photograph of Alfred Russel Wallace, taken in Singapore, 1862. Photograph of Alfred Russel Wallace, taken in Singapore, 1862.
Source: In the public domain, sourced from Wikimedia Commons.
 

After trying his hands at a few trades, Wallace became a field collector – a career that combined his desire to travel with his passion for natural history. After four years collecting along the Amazon River (and an eventful return voyage to England in which he spent 26 days in a lifeboat after his ship caught fire and sank!), Wallace set off for the Malay Archipelago – what is now Malaysia and Indonesia – and spent nearly eight years collecting shells, insects, reptiles mammals and birds for sale in England. The book he published about this trip, The Malay Archipelago, the land of the orang-utan and the bird of paradise; a narrative of travel, with studies of man and nature, was one of the best selling travel books of the nineteenth century.

Museum Victoria has around 200 bird specimens collected by Wallace on this trip that were sold to John Gould and then donated to the museum. Birds are very important in Wallace's story - not only was he looking specifically for the highly sought after birds of paradise on his trip so he could sell them to collectors in England, but his observations about the distribution of birds amongst the islands he visited were highly important in allowing him to develop the theory we today call biogeography – the science of where animals live and why.

Shelf of bird mounts A shelf of bird mounts collected by AR Wallace in the Museum Victoria collection.
Image: Ursula Smith
Source: Museum Victoria
 

In June of 1859 Wallace made an unscheduled trip between the islands of Bali and Lombok when he couldn't find a direct boat from Singapore to Makassar (at the south end of the island of Sulawesi, then called Celebes). He noticed that even though the islands are within sight of each other and very similar in size, elevation and climate, the bird species on Lombok were very different from those he'd seen on Bali. Wallace came to the conclusion that the two islands belonged to distinct Zoological provinces. He wrote in The Malay Archipelago:

I may mention that during a few days' stay in the island of Bali I found birds of the genera Copsychus, Megalaima, Tiga, Plocus, and Sturnopastor, all characteristic of the Indian region and abundant in Malacca, Java, and Borneo; while on crossing over to Lombock, during three months collecting there, not one of them was ever seen; neither have they occurred in Celebes nor any of the more eastern islands I have visited. Taking this in connexion with the fact of Cacatua, Tropidorhynchus, and Megepodius having their western limit in Lombock, we may consider it established that the Strait of Lombock (only 15 miles wide) marks the limits and abruptly separates two of the great Zoological regions of the globe.

In a paper about the distribution of birds in 1868 T.H. Huxley labelled this boundary that Wallace had described between the Asian and Australian biological regions as 'Wallace's Line', the name by which we still know it today. Since then we've discovered that there are other boundaries passing through the archipelago that are relevant to groups other than birds, but Wallace's Line remains the best known and the area is still an important location for research today.

Bird collected by Wallace Bird specimen, an adult female Eclectus Parrot, in the MV collection that was collected by AR Wallace.
Image: Ursula Smith
Source: Museum Victoria
 

Links:

Meet Me at the Museum: Birds of Paradise

Capturing Paradise: Alfred Russel Wallace's Red Bird of Paradise

Ornithology Collection

Entomology Collection

Wallace's books available as free ebooks from Project Gutenberg

Murchison meteorite

Author
by Ursula
Publish date
5 December 2011
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Comments (5)

Ursula Smith works in the natural sciences collections at Museum Victoria. Though a palaeontologist by training she finds all the collections fascinating and swings between excitement at all the cool stuff in them and despair at the lack of time to look at it all.

I’ve been asking the people who work with MV collections what some of their favourite items are, starting with Dermot Henry, the Manager of the Natural Sciences Collections.

Dermot's speciality is geology and he’s looked after the geosciences collections for many years. When asked what his favourite item was he took care to tell me that he didn’t have a favourite because there are so many fascinating objects, but when pressed he picked the Murchison meteorite as "probably the most famous and scientifically important rock in the collections."

The Murchison meteorite is one of 16 meteorites known from Victoria, and is rare in that it was actually observed falling, rather than just being found on the ground, so it came to scientists fresh (other than some surface dirt from falling into mud and cowpats and the like). It exploded in the atmosphere over Murchison, Victoria, about 160km north of Melbourne, on 28 September, 1969 and fell over an area around 35km2. So when we talk about 'it' we’re really talking about lots of broken pieces of a single object.

  Geology exhibition display Display in Dynamic Earth.
Image: Ursula Smith
Source: Museum Victoria
 

These pieces are on display in Dynamic Earth and are just a very small portion of what was collected. The largest piece found weighed nearly 7kg though many more were just a few grams each. In total, around 100kg was collected and over 80kg of that made it into science collections. While a lot of the material went overseas (mostly to the Field Museum in Chicago who have nearly 52kg and the Smithsonian in Washington DC who have nearly 20kg) some remained in Australia. Over 7kg stayed at the University of Melbourne and much of this was later donated to Museum Victoria. We have about 3.5kg and only the largest pieces that are on display; we also have lots of smaller pieces.

Drawer containing pieces of Murchison meteorite Drawer containing pieces of Murchison meteorite.
Image: Ursula Smith
Source: Museum Victoria
 

Most of the pieces of rock in this drawer are parts of the Murchison meteorite (though not the big rock on the right – that’s actually a different meteorite of a similar type called Rainbow that was found in Victoria in 1994). Opening the sealed tubes, you can still smell, very faintly, what Dr. John Lovering from the University of Melbourne who organised the collection of the meteorite pieces in 1969 described as "just like methylated spirits – very strong". This was the first indication that the meteorite he was looking at was a rare type called a carbonaceous chondrite. Unlike more common rocky meteorites, a carbonaceous chondrite is packed full of organic molecules and a lot of water; this one is eight per cent water.

The year after it was collected, papers began to appear in scientific journals describing the chemical composition of the meteorite and excitement about its scientific significance began to grow. A paper in the journal Nature describing the discovery of amino acids of extra-terrestrial origin in the meteorite made, if you’ll pardon the pun, quite an impact, and was widely covered in the press, even making it into Time Magazine. Papers are still being published on it – one came out in August this year in the Proceedings of the National Academy of Sciences, and a new chromium sulfide mineral, Murchisite (Cr5S6), was just reported in American Mineralogist.

To date over 70 amino acids have been identified from the meteorite, only 19 of which are known from Earth. These, and the many other chemicals that have been identified, suggest there could be thousands of complex organic chemicals present. What’s so interesting about these molecules is that they demonstrate that the simple chemical building blocks necessary for life on Earth seem to form quite easily in other places.

It isn’t just the origins of life that the Murchison meteorite may tell us about. It contains tiny pre-solar grains – nano-diamonds and silicon carbides, among others, that formed in supernovas long before our own sun appeared – which tell us a lot about how our own, and other, solar systems formed. But not only that, information from the pre-solar grains in the Murchison meteorite has been fundamental in figuring out a lot about how elements are originally produced and a lot about the structure and mechanics of stars.

So the Murchison meteorite is definitely pretty cool – biologists, chemists, astrophysicists and those of us who just think rocks that fall out of the sky are fascinating all agree on that. As Dermot says, "it’s so unusual and it’s yielded so much information about cosmology, element formation and how the universe works – it’s probably generated more publications than any other meteorite. And it’s Victorian!"

Murchison meteorite pieces Two pieces of the Murchison meteorite in Dynamic Earth.
Image: Ursula Smith
Source: Museum Victoria
 

Links:

Infosheet: Meteorites

Video: The Murchison meteorite story

Dermot A. Henry, 'Star Dust Memories - a Brief History of the Murchison Carbonaceous Chondrite'. Publications of the Astronomical Society of Australia, 2003. 20: vii-ix (PDF, 1 MB)

Death by octopus

Author
by Ursula
Publish date
4 November 2011
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Ursula Smith works in the natural sciences collections at Museum Victoria. Though a palaeontologist by training she finds all the collections fascinating and swings between excitement at all the cool stuff in them and despair at the lack of time to look at it all.

Given that they're the subject of some major research at the museum there's been a lot of talk about blue-ringed octopuses around the Sciences Department at the museum recently. As I grew up in the UK, I've never seen one so when I heard that there was one on display in Melbourne Museum I headed down to find it so I could see what these fearsome beasts I'd heard so much about look like in the flesh. But to my surprise it didn't look as exciting as I had expected - there was not a blue ring to be seen.

So now I know what any Victorian schoolchild should be able to tell you: a blue-ringed octopus only displays those eponymous blue rings when it feels threatened or disturbed and most of the time it's just a plain brown or greyish colour.

Blue-ringed octopus in jar Blue-ringed octopus (Hapalochlaena maculosa) specimen in a jar on display.
Image: Genevieve Ooms
Source: Museum Victoria
 

Despite this specimen's disappointing colouration though, it does have a fascinating story attached to it. Look closely at the label in the picture and you can just see that it bears the slightly ominous "...bit and caused paralysis" which is a transcription of the note made in the museum registration book when this specimen was donated: "This specimen bit and caused paralysis in its captor". As it happens, this is the actual individual, collected on Christmas Day, 1962, that lead to much of the public awareness about the dangers of the blue-ringed octopus.

It perhaps seems a little strange that it wasn't known that this species is so dangerous until so recently - despite the southern species being described in 1883, it wasn't until 1954 that the bite of any blue-ringed octopus was discovered to be deadly. The first recorded fatality – one of only two in Australia to date – was in spring 1954 near East Point, Darwin, but the culprit was originally misidentified because it got away and was then identified based on another octopus the victim's friend pointed out as looking the same. The victim, a 21 year old seaman, Kirk Dyson-Holland, died within two hours of being bitten after picking up an octopus while spearfishing.

For a while, it was largely assumed that the danger of death-by-octopus was restricted to the north or perhaps to people with specific allergies, but then nearly a decade later, on Christmas Day 1962, Arthur Thompson, then 33, was bitten on the hand by a southern blue-ringed octopus at Ricketts Point, Beaumaris in Port Phillip Bay just round the coastline from Melbourne (where they are still found – there was a report in a local paper of one being picked up by a 4 year old just this May). The Registrar of the Alfred Hospital Clinical Research Unit where Mr. Thompson was taken reported:

The patient held it on the back of the hand for a minute of two, and after putting it down noticed a speck of blood on his hand, there had been no sensation of sting or bite. A few minutes later he felt a prickling sensation around his mouth which rapidly became generalized and within fifteen minutes was almost completely paralysed.....Just after admission spontaneous respiration ceased and he was respired for about an hour. Thereafter he made a steady and uneventful recovery of his muscle power. He was well the next day, chest X-ray was clear and he was discharged.

Happily, Mr. Thompson recovered after an hour of artificial ventilation while the poison wore off and nobody has actually been killed by one in Victoria, but the story of this octopus, reported widely in the news, lead to a much greater awareness of the danger of disturbing the blue-ringed octopus. There has only been one reported fatality in Australia since, near Sydney in 1967, partly due to better understanding of the dangers and partly because the blue-ringed octopus is, fortunately, really quite laid back and won't bite unless provoked.

Mr. Thompson's brush with death obviously wasn't the first time someone was bitten by one of these octopuses and it is likely that there have been other deaths before and after, many of which would have been reported as unexplained. In fact, there was an incident a year earlier in December 1961 at Cowes, Phillip Island, with almost identical results: the victim was bitten, felt gradual paralysis until he stopped breathing, was given artificial respiration for a couple of hours and then recovered to be discharged from the hospital on Christmas day exactly a year before Mr. Thompson was admitted. That octopus wasn't kept so we don't know for sure what species it was, but it seems likely that it was also our friend the blue-ringed octopus.

So next time you visit the museum, keep an eye out for this specimen in the Port Phillip Bay cabinet on the ground floor – just turn left as you come past the ticket desk. It won't bite!

Blue-ringed octopus swimming Blue-ringed octopus, Hapalochlaena maculosa.
Image: Julian Finn
Source: Museum Victoria
 

 

References:

Report of the first fatality in Australia: Flecker H, Cotton BC (1955). Fatal bite from an octopus. Med J Aust 2:329-331.

Injuries to man from marine invertebrates in the Australian Region. Cleland, J. B. and Southcott, R. V. 1965. National Health and Medical Research Council, Canberra, pp282.

 

Links:

Australian Women's Weekly article from 1967

Report from the Moorabbin Leader from May 2011

MV Blog post about Julian's research

Marine Life exhibition

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Updates on what's happening at Melbourne Museum, the Immigration Museum, Scienceworks, the Royal Exhibition Building, and beyond.

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