The oldest chameleon in the World

The oldest chameleon in the World

by Alex Laube Internationaler Chamäleontag

The oldest chameleon in the world comes from Myanmar. More precisely, it was discovered by chance. Myanmar has had commercial amber mines from the Cretaceous period for over a century – probably the only country in the world to do so. The most productive mines of this amber, known as “Burmite”, are located in the Hukawng valley in Kachin in northern Myanmar. These mainly supply the Chinese market, but some are also sold directly to interested private individuals. For years, scientists have repeatedly made highly interesting palaeontological finds among the amber sold.

The chameleon in question, along with other fossils encased in amber, was sold to jewellers who cut the stones into cabochons, a type of gemstone. From there, the pieces were sold to private individuals, including James Zigras and Scott Anderson, private collectors. Scientists were allowed to analyse the ambers and put them in a CT scanner, among other things. It turned out that the little chameleon must have been a juvenile. Almost the entire skeleton and almost the entire skin are preserved. It is only 10.6 mm long and the claws in particular are very well preserved. The overall habitus of the animal suggests that it was a chameleon, only the teeth and the arrangement of the fingers and toes do not quite match today’s chameleons. It is now assumed that this chameleon is over 99 million years old and has been in amber for this long. Of course, it is not a species of chameleon that exists today, but it is a relative. It is called a “protochameleon”, which means it is a precursor to our modern chameleons. In the picture above, the chameleon can be seen at the bottom right, in the amber measuring 1 cm below. This amber is still in a private collection and not in a museum.

…to clarify another question that you have probably asked yourself, but which has not yet been answered: As far as we know, Parson’s Chameleons from Madagascar are the oldest of all chameleons. Individual males that are over 20 years old are known from herpetoculture.

#show your colours #internationalchameleonday #chameleonday #chameleondayMay9 #agchamaeleons

Photo: Various fossils in amber, source: Juan D. Daza, Edward L. Stanley, Philipp Wagner, Aaron M. Bauer, David A. Grimald; Mid-Cretaceous amber fossils illuminate the pastdiversity of tropical lizards, Download

Addendum: Unfortunately, it has since emerged that the little creature in the amber is not a chameleon at all. The oldest chameleon is therefore not from Myanmar after all!

 

Why do chameleons change colour?

Why do chameleons change colour?

by Alex Laube Internationaler Chamäleontag

It is a myth that chameleons can choose their colours according to what they are sitting on. It is also not true that chameleons can adapt to their background and become virtually “invisible”. In fact, chameleons use their ability to change colour to communicate and express their mood. Bright colours are intended to impress opponents. High-contrast patterns in females indicate that they are pregnant. Pale colours show that one opponent is inferior to another, that it is not breeding season or that the chameleon is not doing so well. Incidentally, the proverb about “turning black” fits the chameleon perfectly: when chameleons are in a very bad mood, they actually turn black.

Each chameleon species has a limited colour spectrum at its disposal. The colour change itself is caused by guanine crystals in the skin and takes place unconsciously. And even within the individual species, each chameleon can only take on certain colours. In panther chameleons, for example, where the males are known to be particularly colourful, green skin can turn yellow or orange when excited, blue skin can even turn white, but red skin can only change in intensity.

And then there are also terrestrial leaf chameleons, which are not “typically colourful chameleons”. But they are just as colourful as chameleons, only less well known. Due to their habitat on the ground, they mainly wear brown and beige colours.

#show your colours #internationalchameleonday #chameleonday #chameleondayMay9 #agchamaeleons

Pictures:
Panther chameleon in a calm (left) and excited state (right), source: Jérémie Teyssier, Suzanne V. Saenko, Dirk van der Marel, Michel C. Milinkovitch, Photonic crystals cause active colour change in chameleons, Download
Chamaeleo zeylanicus in different colours throughout the day, photographed by Dr. Raju Kasambe, Creative Commons Attribution-Share Alike 4.0 International
Bradypodion damaranum, Bradypodion transvaalense and Bradypodium caffrum, Colouration in dominant (left) and inferior (right) males, source: Devi Stuart-Fox & Adnan Moussalli, Selection for Social Signalling drives the evolution of chameleon colour change, Download

 

What do chameleons eat?

What do chameleons eat?

by Alex Laube Internationaler Chamäleontag

Most chameleons are insectivorous, i.e. they feed on insects, arachnids, arthropods and other small animals. Depending on their size, their diet can range from flies, moths, wasps, butterflies and grasshoppers to praying mantises or spiders. Small, ground-dwelling chameleons in particular also feed on woodlice, springtails and aphids. The largest chameleons, on the other hand, do not spurn the occasional small bird or gecko. As many travellers and chameleon keepers have observed, chameleons are opportunists when it comes to food. If a young chameleon is nearby and it would fit well in their mouth, they will sometimes shoot a much smaller fellow chameleon off a branch and eat it. Fortunately, this is not the rule. A few chameleon species are also known to eat plant leaves from time to time. For centuries, chameleons were thought to be pure ambush hunters. In fact, this is not quite true. They are so-called “cruise foragers”, that don’t just wait in one place for food, but go hunting at a very leisurely pace.

#show your colours #internationalchameleonday #chameleonday #chameleondayMay9 #agchamaeleons

Picture: Chamaeleo chamaeleon schießt ein Insekt in Kapıçam National Park, Türkei; Creative Commons Attribution-Share Alike 4.0 International, fotografiert von Mkrc85

The largest chameleon

The largest chameleon

by Alex Laube Internationaler Chamäleontag

The largest chameleon in the world – well, actually several species are fighting for the title. There are three contenders: the Meller’s chameleon (Trioceros melleri) from mainland Africa, the Parson’s Chameleon (Calumma parsonii parsonii) from Madagascar and the Madagascar giant chameleon (Furcifer oustaleti).

The Meller’s chameleon is found in the mountains of Tanzania, northern Mozambique and Malawi. The main distribution area is known to be Mount Zomba. The largest chameleon of this species measured to date is said to have measured 76 cm from the tip of its nose to the tip of its tail and weighed 600 g. The Parson’s chameleon, on the other hand, is found in various places on the central and southern east coast of Madagascar. Here, the largest chameleon measured so far is said to have been 72 cm long, but there are even measurements of over 700 g in weight. The Parson’s Chameleon is therefore definitely heavier, and the size of some animals comes close to that of the Meller’s chameleon. That leaves the Madagascar Giant Chameleon. It reaches almost 70 cm and, despite its sometimes impressive size, it almost always weighs less than 500 g. So despite its name, it will probably have to make do with third place.

#show your colours #internationalchameleonday #chameleonday #chameleondayMay9 #agchamaeleons

Pictures:
Trioceros melleri,  Creative Commons Attribution 4.0 International, photographed by John Lyakurwa
Calumma parsonii parsonii, Creative Commons Attribution-Share Alike 4.0 International, photographed by von Jialiang Gao
Furcifer oustaleti, Creative Commons Attribution-Share Alike 4.0 International, photographed by Sharp Photography

The smallest chameleon of the Earth

by Alex Laube Internationaler Chamäleontag

The world’s smallest chameleon is also the world’s smallest amniote. It is called Brookesia nana – Nano chameleon – and was only discovered in 2021. Given its size, this is hardly surprising – it is only 22 mm long! The male is even a little smaller than the female, which at 29 mm in total length is no giant either. Its home is the island of Madagascar in the Indian Ocean, more precisely in the Sorata Massif in northern Madagascar. It lives in layers of foliage at the foot of large trees. There is another exciting feature: in relation to its body size, the male of this species has incredibly large hemipenes! Yes, chameleons have two penes instead of a single penis – handy if one breaks. But in the nano chameleon, the hemipenes make up 18.5% of the total body length. In humans, that would be the same as if the penis of a 1.80 metre tall man were 33 cm long.

But back to the nano chameleon itself. Despite its tiny size, like many other chameleon species it reproduces by laying eggs in the foliage. These hatch into even tinier young, which feed on the smallest micro-insects on the ground. Overall, however, the tiny creatures are likely to have a relatively hard time in the rainforest, as even any spider is bigger than them and certainly sees a small chameleon as a welcome change on the menu, but in fact the main threat to the small chameleons is humans. The nano-chameleon was probably already threatened with extinction before it was discovered.

The discovery was a pretty big deal at the time. It was reported everywhere, for example in Die Welt, auf National Geographic, bei Scinexx, im GoodNews Magazin oder bei der Frankfurter Allgemeine Zeitung. You can download the original publication for free here. And what we still don’t know: Is there perhaps even a smaller chameleon? After Brookesia minima, Brookesia micra and Brookesia nana, the only thing missing is Brookesia pika. Madagascar has already had a few surprises in store… maybe this one too?

#show your colours #internationalchameleonday #chameleonday #chameleondayMay9 #agchamaeleons

 

Video: EndangeREX, Timon Glaw

How to identify chameleons

How to identify chameleons

by Alex Laube Internationaler Chamäleontag

Identifying chameleons – Did you know that there is a platform where you can post any of your chameleon observations online while travelling? Anyone can share their photographed observations with others on iNaturalist. You can also have chameleons that you were unable to identify yourself identified by experts. Some people from the Chameleons working group are also represented there! Scientists and curious people from all over the world can view the observations and find new locations or unknown species from the comfort of their own homes. Or make exciting observations – such as this recent publication on mosquito bites in chameleons.

#show your colours #internationalchameleonday #chameleonday #chameleondayMay9 #agchamaeleons

Picture: Trioceros deremensis, photographed by Simon Tonge

Chameleon species worldwide

Chameleon species worldwide

by Alex Laube Internationaler Chamäleontag

Do you know how many chameleons there are in the world? There are currently exactly 228 species! Most of them are found in Africa, over 40% of them only on the island of Madagascar. But there are also chameleons in southern Spain, Italy, Turkey and India. They range from brightly coloured to small and brown, from tiny to huge. An incredible variety makes this group of reptiles unique. And not all species have been described yet!

Here is a list of all currently known chameleon species, each with a link to the ReptileDatabase for further information:

#show your colours #internationalchameleonday #chameleonday #chameleondayMay9 #agchamaeleons

Foto: Trioceros hoehnelli, fotografiert von Marius Burger

International Chameleon Day

International Chameleon Day

by Alex Laube General topics

Finally, the world’s most colourful reptiles have their own day! Wildlife Madagascar has proclaimed 09 May as INTERNATIONAL CHAMÄLEON DAY. And the AG Chamäleons is of course taking part. From 00:00 on 9 May 2024, we will be posting facts, exciting information, links and games about chameleons every hour. For 24 hours! We are looking forward to it!

#show your colours #internationalchameleonday #chameleonday #chameleondayMay9

Sex chromosomes in chameleons

Sex chromosomes in chameleons

by Alex Laube Science

Which sex chromosomes are present in chameleons has so far been studied rather sparsely. The Madagascan chameleon genus Furcifer is known to have Z and W chromosomes, although sometimes several Z chromosomes occur, so-called neo-sex chromosomes. Recently in the Czech Republic, scientists examined this deeper.

Blood and tissue samples were taken from 13 chameleons to isolate DNA. The animals sampled included one male and one female each of the species Brookesia therezieni, Calumma glawi, Calumma parsonii, Chamaeleo calyptratus, Furcifer campani, Furcifer labordi, Furcifer lateralis, Furcifer oustaleti, Furcifer pardalis, Furcifer rhinoceratus, Furcifer viridis, Kinyongia boehmei and Trioceros johnstoni. Only in Furcifer oustaleti were two females sampled. Subsequently, the Z1 chromosomes of the panther chameleons and the Z and W chromosomes were analysed by microdissection. Gene coverage analyses were performed for carpet and panther chameleons. In addition, qPCRs were performed to compare the homology of the Z chromosomes.

The results show that the morphology of the Z1 chromosomes of panther chameleons corresponds to the Z chromosome of the entire genus Furcifer. The Z1 chromosome of panther chameleons thus corresponds to the Z chromosome of Furcifer oustaleti. The Z2 chromosome of panther chameleons, on the other hand, is a neo-sex chromosome. Both the Z and W chromosomes in Furcifer oustaleti are probably pseudautosomal. 42 genes have been described as specific for the W chromosome.

A total of 16,947 genes were identified in Furcifer lateralis and 16,909 genes in Furcifer pardalis. The ratio of the number of genes between females and males is 0.35 and 0.65 for the two species. In panther and carpet chameleons, most of the genes on the W and Z chromosomes were found to be the same, with relatively few genes found only on the W chromosome. This finding is surprising, as the researchers had actually expected that the heterochromatic W in Furcifer species would have lost most of its genes compared to the Z chromosome.

The sex chromosomes of the genus Furcifer probably evolved at least 20 million years ago, which roughly corresponds to the time when the species Furcifer campani split off from the other Furcifer species.

Heteromorphic ZZ/ZW sex chromosomes sharing gene content with mammalian XX/XY are conserved in Madagascan chameleons of the genus Furcifer
Michail Rovatsos, Sofia Mazzoleni, Barbora Augstenová, Marie Altmanová, Petr Velenský, Frank Glaw, Antonio Sanchez, Lukáš Kratochvíl
Scientific Reports 14, 2024: 4898.
DOI: 10.1038/s41598-024-55431-9