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DISPLAYING POSTS FROM: Dec 2011 (19)

How to dig for dinosaurs

Author
by Lisa
Publish date
19 December 2011
Comments
Comments (7)

Lisa works in the Public Programs Department at Melbourne Museum but also volunteers in the Palaeontology Department and has been on several fossil digs.

Have you ever wondered what it would be like to go on a dinosaur dig? Recently I went on a fossil-hunting adventure with a crew of 12 Museum Victoria staff and volunteers at a site called Eric the Red West in Cape Otway National Park.

120 million years ago this part of Australia was a river valley surrounded by forest. When the valley flooded, the remains of dinosaurs, small mammals, pterosaurs and forest plants (which became the coal that we see in the rock) were washed into the river. Eventually some of these bones, as well as those of animals such as fish and turtles that were living in the river, became covered by sand and mud. Over time the sediment became the grey sandstone that is exposed on beach today.

palaeontology fieldwork The crew heads down to the site.
Image: Lisa Nink
Source: Museum Victoria
 

When we first arrived on site we unloaded all of our gear and took it down onto the beach. Before we started any digging we prospected along the beach for fossils that were naturally exposed through weathering of the rock.

Prospecting and fossil finds Left: Lesley Kool and Mary Walters in search of fossils weathering out of the rock. | Right: Part of a dinosaur limb bone.
Image: Lisa Nink
Source: Museum Victoria
 

Next it was time to bring out the heavier equipment to remove rock and search for fossils that were still buried. We used large rock saws, small electric saws, sledgehammers and chisels to remove large chunks of the fossil-bearing rock.

tools to remove rock Travis removes sand from the rock with a shovel and Gerry removes chunks of rock with a sledge hammer and chisel.
Image: Liza Nink
Source: Museum Victoria
 

Removing fossils with tools. Left: David Pickering uses a small electric saw to delicately remove a fossil. | Right: Dr Erich Fitzgerald uses a larger rock saw to not so delicately (but precisely) remove a fossil.
Image: Lisa Nink
Source: Museum Victoria
 

When large chunks of rock have were removed and checked for fossils, the rest of the crew used smaller hammers and chisels to carefully break the rock down to sugar-cube sized pieces in search of tiny fossils.

Searching for fossils Left: David Pickering uses a hand lens to inspect a newly exposed fossil. | Right: Astrid patiently chisels away at rock in search of delicate fossils.
Image: Lisa Nink
Source: Museum Victoria
 

And we were well rewarded for our efforts:

Dr Erich Fitzgerald points to a fossil fish jaw Dr Erich Fitzgerald points to a fossil fish jaw he has just discovered in the rock.
Image: Lisa Nink
Source: Museum Victoria
 

Despite the rain and cold it was a wonderful experience. My friends and colleagues often ask me, 'doesn't it get boring breaking rocks on a beach all day?' but it never does. You never know when the next strike of your hammer and chisel may reveal a new fossil that hasn't seen the light of day for 120 million years. You never know, it may even be a completely new species.

You can see some of the fossils that have been found along Victoria's coastline in 600 Million Years: Victoria evolves at Melbourne Museum.

Links:

Dinosaur Dreaming Blog

MV Blog: Dinosaur Dreaming Dig

Infosheet: Inverloch fossil site

A moth flurry on the Murray

Author
by Mark Norman
Publish date
15 December 2011
Comments
Comments (1)

Mark is Head of Sciences at Museum Victoria. He's reporting back from Neds Corner in this series of blog posts.

There was a flurry of excitement among our moth team over the diversity of moths and some exciting new records for the region and state. Members of the Entomological Society of Victoria, Marilyn and Dean Hewish, Grace Lewis, Ken Harris and Josh Grub, set up night light stations with bright mercury vapour lamps in front a large white sheet. They run all night, as different groups of moths arrive at different times of the night. They clocked up over 120 moth species.

Two Neds Corner moths Left:Sceliodes cordalis | Right: A perfectly camouflagued Convolvulus Hawk Moth, Agrius convolvuli.
Image: M. Hewish
Source: M. Hewish
 

There are several theories on why moths come to human light sources. The generally accepted theory is that moths use points of light in the night sky (such as the moon) to orient their flight paths. They keep the brightest light at a particular angle to their flight direction in order to fly straight. As they go past our electric lights they keep turning inwards to maintain the correct angle until they spiral into the porch light or the light station sheets.

The arriving moths came in all shapes and sizes. Two of the weirdest were the Twisted Moth and the plume moths. The Twisted Moth contorts its body as part of its camouflage to look very not-moth-like. The plume moths have long narrow wings with the rear pair hidden under the front pair. They get their name from the feathery tips to their wings.

Two Neds Corner moths Above: Twisted Moth, Circopetes obtusata looks just like a dry eucalyptus leaf. | Below: A plume moth, Stenoptilia zophodactylus
Image: M. Hewish
Source: M. Hewish
 

Colour patterns ranged from the excellent camouflage of the hawk moths that perfectly match the grey tree bark to brightly coloured forms including some with false eye spots, known as ocelli.

Two brightly-coloured Neds Corner moths Two brightly-coloured Neds Corner moths. Left: Pale Spotted Tiger Moth, Amata aperta | Right: Grammodes ocellata with beautiful eye-spots, or ocelli.
Image: M. Hewish | D. Hewish
Source: M. Hewish | D. Hewish
 

The wood moths (family Cossidae) caused the most excitement. These beautiful moths are not particularly common and the three species found included two ornately-patterned species and a third smaller species that is a new record for Victoria. The males of these moths (and many other moth groups) can be recognised by their large feather-like antennae. These are the chemosensory organs of the males, used to 'smell' the pheromones released by the females. By contrast, females have much narrower, less-feathery antennae.

two wood moths Two wood moths. Left: Endoxyla sp. | Right: Endoxyla neuroxantha representing a new Victorian record for this species.
Image: M.Hewish
Source: M. Hewish
 

Bush Blitz is a biodiversity partnership discovery program between the Australian Government, BHP Billiton and Earthwatch Australia, that aims to document the plants and animals across Australia's National Reserve System. Museum Victoria also participated in Bush Blitz at Lake Condah in March 2011.

Interactive PDF trial

Author
by Alexandra
Publish date
13 December 2011
Comments
Comments (3)

Alexandra is the Early Learning Program Coordinator at Scienceworks. She loves exploring the ways in which science engages young children.

The first trial of the Nitty Gritty Super City interactive PDF on iPads went well last week!

child playing with iPad Child playing with an iPad at the trial of the interactive PDF.
Image: Jackie McWiliam
Source: DEECD
 

The interactive PDF was designed to work like a series of games based on the much-loved Nitty Gritty exhibition content. It functions like a low-tech app, and will soon be available to download from the Scienceworks education pages. It is full of physical and environmental science concepts specifically developed for early learners, in accordance with the Early Years Learning and Development Framework.

woman sitting in front of group of children Alexandra demonstrating the Nitty Gritty Super City interactive PDF section about microscopes.
Image: Jackie McWiliam
Source: DEECD
 

Out of the group of 22 four and five year olds, two children had iPads at home and five children said they had seen an iPad before.

When I showed the children the iPad for the first time, I asked the group, 'What is this?' One child yelled at the top of his voice, 'It's an iPad!'

When I asked the group what an iPad was, one child said, 'It's a rectangle!' Completely wonderful.

children playing with iPads Kids learning what to do when the 'Oops!' screen pops up.
Image: Jackie McWiliam
Source: DEECD
 

And while we have a little tweaking to do based on this inaugural trial, apparently Christmas came to Laverton Children's Community Centre a little early this year.

Links:

Nitty Gritty Super Kids

Meet Me at the Museum episode 2

Author
by Dr Andi
Publish date
12 December 2011
Comments
Comments (3)

Here is episode two of 'Meet Me at the Museum', a video series about our collection.

We marvel at how particular specimens made it into our collection.

Let us know what you think in the comments section. And be sure to see our previous episodes if you haven't already.

 

Watch this video with a transcript.

Total Lunar Eclipse

Author
by Tanya
Publish date
8 December 2011
Comments
Comments (3)

I don’t know about you, but I’m already feeling the pressure of December madness. Really it’s a fantastic time of the year when we catch up with friends, celebrate with colleagues and generally wind things up for the summer. But cramming all this in alongside final deadlines and the Christmas shopping can be a mighty task!

When it all gets a bit too frantic and crazy, there’s nothing like sitting back and taking in the night sky. And this month, there’s even more reason to do so.

This beautiful composition shows the extent of Earth's shadow. It was taken from Europe, so might recognise that the Moon appears upside down.This beautiful composition shows the extent of the Earth's shadow. It was taken from Europe, so you might notice that the Moon appears upside down.
Source: Laurent Laveder

During the early hours of Sunday 11th December there will be a Total Lunar Eclipse. We can watch the Moon change colour as it plunges into the Earth’s shadow.  

The eclipse begins at 11:46pm (AEDT) on Saturday 10th December as the Sun, Earth and Moon fall into line. At first, the shadow will appear to take a bite out of the Moon. Then, the Moon will enter full shadow or totality, just after 1am on Sunday morning. It will stay in shadow for 51 minutes, a little on the short side for a lunar eclipse as they often continue for over an hour.

By 2am, the Moon will begin to light up again and it’s amazing how bright that first glimpse can be. At 3.17am all will be back to normal.

The interesting thing about an eclipse is that the shadow isn’t completely dark. The Moon takes on a reddish glow as light travels through the Earth’s atmosphere. Depending on conditions, it can also take on a hint of blue around the edges from light that passes through the ozone layer in the Earth’s upper atmosphere.

So what might we see during this eclipse? On NASA’s Science news website, atmospheric scientist Richard Keen of the University of Colarado says:

"I expect this eclipse to be bright orange, or even copper-coloured, with a possible hint of turquoise at the edge."

Sounds lovely, doesn't it? Apparently our atmosphere is nice and clear at the moment. Let's just hope the clouds stay away.

Best to try for this eclipse as we are coming up to some lean years. The next lunar eclipse will be a partial in June 2012. But to see a Total Lunar Eclipse, we'll have to wait until April 2014.

The Moon plunges into the Earth's shadow.The Moon plunges into the Earth's shadow.
Source: Public Domain

Eclipses are uncommon because the Moon's orbit (shown in green) is misaligned with the Earth's orbit around the Sun (shown in blue). If the Moon and Earth orbited in the same plane, we'd see an eclipse every Full Moon (as well as a solar eclipse every New Moon). But because the Moon's orbit is tilted by just 5 degrees, most of the time the Moon misses the Earth's shadow and moves either above or below it.

So enjoy taking some time out to appreciate the Universe we live in, as long as the weather lets us!

 

Spider city

Author
by Mark Norman
Publish date
7 December 2011
Comments
Comments (2)

Mark is Head of Sciences at Museum Victoria. He's reporting back from Neds Corner in this series of blog posts.

One of the priority groups of animals for the Bush Blitz surveys is the primitive mygalomorph spiders, such as trapdoor spiders and tarantulas. This group of spiders have large fangs that point down and can only be used to pin and pierce their prey. The 'modern' spiders (araneomorphs) have fangs that turn towards each other, so can be used more easily to grab their prey. We found only one small mygalomorph spider species.

Mygalomorph spider Mygalomorph spider
Image: M Norman
Source: Museum Victoria
 

Wolf spiders are the other focus group for these surveys and we found them everywhere. Dr Barbara Baehr from Queensland Museum was the wolf spider expert on the team. On night walks the blue eye shine of hundreds of wolf spiders can be seen over the ground and in the trees. Some larger ones build trapdoors over their burrow, complete with a perfect hinged lid.

Wolf spider and burrow Left: Wolf spider | Right: Wolf spider burrow with trapdoor
Image: Patrick Honan | Mark Norman
Source: Museum Victoria
 

The huntsman spiders here were very impressive, being among the largest in Australia with the females reaching 20cm across. Close-up images showed that many had small red mites crawling over their bodies.

huntsman spider Huntsman spider
Image: David Paul
Source: Museum Victoria
 

A Redback Spider nest was found by BHP participant Paul Simper where a large female was guarding two round egg masses while the tiny attendant male sat nearby.

Redback Spider family A Redback Spider family - the large female is in the centre, with the small male to the left and an egg sac to the right.
Image: David Paul
Source: Museum Victoria
 

The list of other spider types at Neds Corner is long, and includes ant spiders, ant-mimicking spiders, jumping spiders, orb weavers, social spiders, crab spiders and cellar spiders.

Ant spider Ant spider (family Zodariidae).
Image: Mark Norman
Source: Museum Victoria
 

Bush Blitz is a biodiversity partnership discovery program between the Australian Government, BHP Billiton and Earthwatch Australia, that aims to document the plants and animals across Australia's National Reserve System. Museum Victoria also participated in Bush Blitz at Lake Condah in March 2011.

Links:

Parks Australia blog

Bush Blitz

Neds Corner Station

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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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