Kadimakara australiensis facts for kids
Quick facts for kids Kadimakara australiensis |
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| Holotype (A,B) and referred snout (C,D) of Kadimakara australiensis | |
| Scientific classification | |
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Kadimakara
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australiensis
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Kadimakara was an extinct reptile that lived a very long time ago. It belonged to a group called archosauromorphs. These ancient reptiles are related to modern crocodilians, pterosaurs (flying reptiles), and dinosaurs. Kadimakara lived in Queensland, Australia. Its name comes from old Aboriginal myths about giant prehistoric creatures. The second part of its name, australiensis, simply means it was found in Australia. It was a close relative of another meat-eating reptile called Prolacerta.
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How Kadimakara Was Discovered
Scientists only know about Kadimakara from parts of its skull. The main fossil, called the holotype, is known as QMF 6710. It includes the back part of the skull and a piece of the lower jaw.
This fossil was found in the mid-1970s. It came from a fossil site about 72 kilometers (45 miles) southwest of Rolleston, Queensland. The rocks where it was found are from the Rewan Group. These rocks date back to the Induan age, which was about 251 million years ago. This was right at the beginning of the Triassic Period. At that time, life on Earth was just starting to recover from a huge extinction event.
Another skull piece was found at the same site. This piece, QMF 6676, was a part of the snout and lower jaws. Since it didn't overlap with the first fossil, scientists can't be 100% sure it belonged to Kadimakara. However, there's nothing to suggest it didn't. Like other fossils from the Rewan Formation, the Kadimakara remains were covered in hematite (a type of iron ore). Scientists had to use a special acid to carefully clean them.
What Kadimakara Looked Like
Kadimakara was about half the size of its relative, Prolacerta. But based on the skull bones found, it looked quite similar.
The Main Skull Fossil
The main fossil (holotype) shows the back of the skull. It includes bones called parietal bones, which form the top of the skull behind the eyes. These bones were box-shaped and met in the middle of the skull.
In the middle of these bones was a small hole called a pineal foramen. In some modern reptiles, this hole holds a sensory organ. People sometimes call it a "third eye". Just behind this hole was a rectangular lowered area. This special lowered area helps scientists tell Kadimakara apart from Prolacerta.
Above the eyes were bones called frontals. Only a small part of these bones was found. But it shows that the parietal bones stretched forward to the level of the eyes. Kadimakara also didn't have postparietals. These are extra bones that form at the back of the parietals in many other archosauromorphs. These skull features link Kadimakara closely to Prolacerta.
The Snout Fossil
This fossil might not definitely belong to Kadimakara, but it looks very much like the snout of Prolacerta. The maxilla (the main bone in the snout with teeth) had a normal shape. It also had shallow grooves on its surface.
Several teeth were found attached to the maxilla. These teeth were sharp, curved, and flattened from the side. This tells us that Kadimakara was a meat-eating reptile. The teeth were set deep in sockets and attached to the bone. The back edge of the maxilla connected to a smaller bone called a lacrimal. This bone formed the front edge of the eye socket.
The top of the snout was made of two large bones called nasals. These likely connected to the frontal bones, but that part wasn't preserved. The middle part of the lower jaw was also found. It had teeth similar to those in the maxilla.
Kadimakara's Family Tree
How Kadimakara and Prolacerta fit into the reptile family tree has changed over time. When Kadimakara was first described in 1979, scientists were still trying to figure out Prolacerta.
At first, Prolacerta was thought to be an ancestor to all modern reptiles. But in 1975, a scientist named Chris Gow noticed something important. The teeth of Prolacerta (and Kadimakara) were very similar to those of a group called 'thecodonts'. We now call this group archosauromorphs. This idea was supported by later studies, including the first description of Kadimakara.
Over the years, scientists refined the group 'Thecodontia'. They replaced it with the more specific group Archosauromorpha. This group includes all reptiles that are more closely related to crocodiles and dinosaurs than to lizards and snakes. For a while, Kadimakara and Prolacerta were placed in a group called Prolacertiformes. This group also included other long-necked archosauromorphs like Protorosaurus and Tanystropheus.
However, in 1998, a study by David Dilkes showed that Prolacertiformes was not a true group. It contained reptiles that were only distantly related. Most importantly, Prolacerta was found to be more closely related to the advanced Archosauriformes. These are the ancestors of crocodiles and dinosaurs.
For a long time, Kadimakara was left out of these studies. This was because its fossils were incomplete. So, scientists weren't sure if Kadimakara was truly a close relative of Prolacerta. Some even thought Kadimakara might just be misidentified Prolacerta fossils.
Finally, in 2016, Martin Ezcurra did a big study on archosauromorphs. He looked at Kadimakara again and found evidence that it was indeed a separate genus from Prolacerta. His study showed that Kadimakara was the closest relative to Prolacerta. These two genera form a family called Prolacertidae. They are positioned near the Archosauriformes, just as earlier studies had suggested.
