Category Archives: Reptiles & Amphibians

It’s Taxon Time

Written by: Maryanne Venables, Strategic Learning

The “Zoo Animals” went into the tin with the blue lid, while my “Farm Animals” went in the tin with the green lid. The animal kingdom, as I knew it, lived under my bed in Streets ice-cream tins. All were classified, according to contexts developed from the songs, books and experiences of a four-year old. Fast forward to 2012 and, as a Museum Educator, I am delighted to be sharing the topic of Animal Classification with the next generation of biologists, taxonomists or collectors.

Queensland Museum has re-launched Animal Classification into our range of school programs. Bookings are now being taken for Yr 3-7* classes to experience a value-added program to enrich your Museum visit

If the  concept of Animal Classification makes you numb, let us please change your mind. School programs are delivered by the Museum Learning team, using real collections to elicit real experiences. This is a valuable option in an increasingly virtual world.

Students can interact with real museum specimens

This program primarily responds to Science Understanding descriptors in Australian Curriculum: Science for Yrs 3 and 7, but also addresses Science as a Human Endeavour and Science Inquiry Skills for Yrs 3-7.

So how does classification apply to our lives? You don’t even need to be a collector to use it. We find classification systems everywhere – from libraries to supermarkets. Things that are in some way similar are arranged together for comprehension and convenience.

So how does animal classification apply to our lives? Animals are grouped as part of the process that describes or identifies them down to an individual species. This helps us effectively communicate information about them. Understanding characteristics of a particular species or group can affect our health and welfare, economic growth and ability to effectively manage the conservation of our wildlife.

Dr Karl Kruszelnicki has shared the virtues of the dung beetle since the CSIRO introduced several species to Australia in the late 1960s. The objective was to manage a bi-product of grazing and its impact on fly control (the bi-product that wasn’t destined for our taste buds or footwear). Selected species were introduced to a number of Australian climates and ecosystems resulting in a biological control success story. Our approx 350-400 species of native dung beetle evolved to mostly feed on the smaller, drier, fibrous dung pellets of marsupials.

The hard-working Honeybee

Other examples of genus-specific relationships are applied in agriculture (both in pollination and pest management). According to the Queensland Department of Agriculture, Fisheries and Forestry, Honeybees add an estimated $4 – 6 billion to Australian agricultural and horticultural industries, annually.

Further examples of identified animal groups have supported medical research. Studies of Tammar Wallaby and other marsupial forms of milk have provided medical researchers with a template for investigating antimicrobial compounds, potentially resistant to “superbugs”.

Examples of animals helping humans can be ‘reciprocated’ in conservation campaigns. Most Queenslanders are aware of the plight of the endangered Northern Hairy-nosed Wombat. Distribution once extended south to the Victorian border. By the 1980s, a drastically reduced population was reportedly (without the advanced surveying methods in use, today) around 35 wombats. A remnant population in Epping Forest National Park (South-West of Mackay, Queensland) was recognised as the last chance to protect this species. Since then, wombat numbers have been carefully monitored and protected, reaching around 138 today. In 2009, the colony was deemed at risk should an environmental disaster such as fire or flood affect the region. To mitigate this, the decision was made to establish a second breeding colony 600km south at Richard Underwood Nature Refuge (near St George, Queensland). Recent reports (May 2012) indicate this second population is stable with the current “snout count” at seven females, three males and three joeys in good condition.

The Northern-Hairy-Nosed wombat is critically endangered

A smaller cousin, the Southern Hairy-nosed Wombat has maintained a conservation status of ‘Least Concern’, although recent reports suggest it, too is affected by similar threats.  These include reduced/replaced food plants and possibly toxins from introduced weeds. Relationships determined by the classification of animals can help us to make informed decisions. Are we prepared to learn from the past to determine the future?

The Animal Classification theme is supported by a range of Queensland Museum exhibitions and resources.

* Please note:  Secondary school, teachers can also select a Biodiversity and Classification program, which can be tailored to your unit of work by prior arrangement.

Does size matter? Misidentification of, and assumptions about, the world’s largest lizard

Humans are fascinated by extremes; just consider the popularity of the Guinness Book of Records. It’s also reflected by our fascination with huge dinosaurs; think Tyrannosaurus rex and Brachiosaurus. So it is not surprising that claims that ‘giant predatory lizards 11m long once roamed Ancient Australia’ would garner attention and intrigue. In fact the lizard was appropriately given the scientific name, Megalania, meaning ‘giant ripper’. But the search for the true size and nature of this giant reptile, reveals a story of misidentification, opposing ideas, inexact science and false assumptions.

Megalania skull replica
Megalania skull replica

The story begins in the 19th Century, with a large number of fossils of a particular type being uncovered by land owners and naturalists. The size of the bones and teeth indicated that the animal was large. Many perceived the fossils to be of a dinosaur and others classified them as crocodilian. It was never dreamt of at the time that they could been the remains of a gigantic lizard (the Komodo dragon was unknown to science at that time). However, as fragments were combined and examined more closely, it gradually became clear that these were the remains of a giant extinct lizard living during the late Pleistocene, approximately 30,000-180,000 years ago.

Well actually, it wasn’t that clear. In fact the science was decidedly murky. Many of the remains were incorrectly labelled for a long time, and were actually the bones of giant land tortoises, giant flightless birds or even giant marsupials. The opposite also occurred, with many bones identified as belonging to these groups, actually being those of Megalania. Debate among palaeontologists over these matters ruffled a few feathers.

But the debate really got heated around the issue of the size of Megalania. Early estimates inferred a length of 3 m, but over time, the body length increased to 9, 10 and even 11 m—stupendously big for a lizard. It was almost as if a competition was being held: “my Megalania is bigger than yours”.

Estimated sizes of the extant monitor lizards Komodo dragon and Perentie, compared to different estimated sizes of the "Megalania" (Varanus prisca).
Estimated sizes of the extant monitor lizards Komodo dragon and Perentie, compared to different estimated sizes of the “Megalania” (Varanus prisca).

The variation in size estimates arises from assumptions that have to be made, largely due to the fragmentary nature of the evidence. For example:

  • The ratio of claw length to body length from living goannas was applied to the fossil claws of Megalania. The only problem was that it is later discovered they were giant flightless bird claws – not Megalania.
  • Determining the head length from skull remains, and then using the head-to-body length ratio of a lace monitor (alive today) to calculate a length of around 7-10 m. However, further research has identified that the ratio is much smaller in komodos and Megalania, so the size was a massive overestimate.

The confusion of the Megalania story intrigued Queensland Museum palaeontologist and Snr. Curator Geosciences, Dr.Scott Hocknull. He recognised that as a key predatory animal, gaining an accurate understanding of it’s biology is essential in understanding the ecology of prehistoric Australia. So Scott travelled the country and even overseas to examine every Megalania fossil he could find.  Meticulous measurements of the remains, and comparison with living goanna species, has helped test many of the assumptions previously made, and identified a total body length of between 5 and 6 m. This still makes it the largest lizard to have ever lived.

Snr. Curator Geosciences, Scott Hocknull, describes some fo the features of a Megalania skull.
Snr. Curator Geosciences, Scott Hocknull, describes some of the features of a Megalania skull replica.

This situation is a prime example of one of the AC: Science learning descriptors within the strand ‘Science as a Human Endeavour’.  ‘Scientific understanding, including models and theories, are contestable and are refined over time through a process of review by the scientific community’ (Yr 9). Science is not always exact, assumptions are made and formulas applied. Scientists are also human and can become attached to particular theories.

So should scientists assume anything? It’s not a very rigorous and reliable methodology is it?  Assumptions are an inescapable and integral part of scientific research. In almost all cases when not everything is known about an object or topic, assumptions simply have to be made. The challenge is to minimise the number of assumptions, and when made, to ensure they are as valid as possible. Scientific investigation in one sense is all about testing assumptions and theories—by different people, using different approaches and as new evidence and material becomes available.

Palaeontology is one area of science particularly susceptible to forming assumptions due to the fragmentary nature and scarcity of evidence. Uncovering a single bed of fossils can overturn theories held for decades. In fact, this is just what is occurring at the moment with the discovery of an enormous fossil bed at South Walker Creek. Scott and his team from QM are investigating this site, and early results indicate that it will substantially expand and change our understanding of Ancient Australian megafauna, including our very own mega-lizard.

Rock Refugia

Patrick Couper is Curator of Reptiles and Amphibians at Queensland Museum and has an active interest in the taxonomy, ecology and conservation of Queensland’s diverse reptile fauna.

Patrick Couper

A major focus of Patrick’s research has been the discovery and description of leaf-tailed geckos that live in the rainforests of eastern Australia. Leaf-tails, which have a long rainforest ancestry, often have strong associations with rocky outcrops. Rocky areas have provided a safe haven for these animals through past periods of climate change. Patrick and Conrad Hoskin (James Cook University, Townsville) have termed such areas, lithorefugia. (Refugia are areas where special environmental conditions have enabled a species or a community of species to survive despite their extinction from surrounding areas.)

Leaf-tailed Gecko, Orraya occultus, from a boulder-strewn creek line in NE Qld

Layered rocky areas are well-buffered from fire and provide cool, moist, stable conditions. These conditions are similar to those found in rainforests.

Black Mountain near Cooktown- typical boulder habitat

The Australian continent was once blanketed with extensive rainforests but as conditions became increasingly arid, these forests contracted to smaller pockets like the remnants now found in coastal Queensland and NSW. As the forests contacted so did their faunas and some rainforest animals retreated to, and survived in, rocky landscapes, many of which are now well isolated from modern rainforests.

During this time, many species became extinct but others survived in these rocky landscapes and produced new species. Recent DNA studies show that many of these rock-dwellers have strong genetic ties to modern rainforest animals. The lithorefugia story is important for understanding the evolutionary processes that shaped Australia’s rainforests and their associated faunas.

There are many examples of rainforest animals that survived in rocky areas. Rainforest snail, spiders, tail-less whip scorpions, and microhylid frogs, such as the Black Mountain Boulder Frog are some examples. There are even mammals that have undergone a shift from rainforest to rock. For instance, the Rock Ringtail Possum that is found in rocky parts of the Kimberley region (WA) and Arnhem Land (NT) has genetic and behavioural characteristics similar to the Green Ringtail Possum, a species now found only in the high altitude rainforests of NE Queensland.

Black Mountain Boulder Frog, Cophixalus saxatilis

The above discussion is relevant to Unit 2 (Change and Survival) of the draft Senior Biology Curriculum. For example, in the Science Understanding strand of this unit is the topic: Evolution of Australian flora and fauna, including

  • significant events in Australia’s geological history and their effect on the evolution of a unique flora and fauna
  • the effect of change in past climates on Australia’s flora and fauna

Species adapt to different conditions as habitats and climates change. To learn more about how climate change has affected the evolution of different animal groups, investigate the online learning resource, Dinosaurs, Climate Change and Biodiversity which contains many teacher and student resources.

To learn more about the work that Patrick does, visit his Biography page.

You can investigate leaf-tailed geckos and other amazing reptiles, by visiting the Reptile section on Queensland Museum’s website.

A LA LA! – Atlas of Living Australia Live At Last

Atlas of Living Australia Live At Last!

The Atlas of Living Australia (ALA) was launched in Brisbane on the 20th May. At a special ceremony held at Queensland Museum (QM), Dr John Hooper (Head of Biodiversity and Geosciences at Queensland Museum) spoke about the collaboration of museums, herbaria, universities and other government collections in producing the ALA.

John Hooper at ALA launch.

The ALA is an online encyclopaedia of all living things in Australia. At present the website holds 23 million distribution records for Australia’s fauna and flora, with over 300 layers for mapping and analysis. It also contains images (under a Creative Commons Attribution licence), maps, identification tools, reference species lists, literature, and databases on biological collections. Here are some images showing diverse molluscs from QM’s collection as well as some colourful sponges.

Although the ALA was only recently ‘switched on’, it is still a work in progress.

The ALA allows us to build and maintain biological collections, assists with research, and aids communication.

You can access the ALA at this link.

To learn more about the biodiversity on the Great Barrier Reef and some factors that are having an impact on this biodiversity, visit the online learning resource Biodiscovery and the Great Barrier Reef. There are lots of teacher notes and student worksheets linked to the new Australian Science Curriculum in this resource.

To learn more about the areas of John’s research, visit his biography page, Dr. John Hooper.