Showing posts with label niche. Show all posts
Showing posts with label niche. Show all posts

Tasmanian Tiger Did Not Fill the Evolutionary NIche of a Dog

It was believed that the Tasmanian Tiger perished in mainland Australia due to the dingo taking over their habitat. New findings show the dingo did not directly compete with the marsupial dog. They had different ways of getting their food.

Dingos were brought to Australia from Asia in recent times. It is not native to Australia. The demise of the Tasmanian tiger on the larger part of Australia 3,000 years ago was coincidental. Settlers in Tasmania feared their cattle and sheep would be slaughtered so they eradicated the quite timid animal in the early twentieth century.

Dingoes are wild dogs that run for long periods running down their prey. Tasmanian tigers were not distance runners. They ambushed sick and young animals. The tiger's skeletal structure was more like cats than dogs, particularly the elbow joint which was feline in character. The dingo has elbows that lock, while the marsupial dog had a flexible joint. This undermines the theory that the Tasmanian tiger filled the evolutionary niche open in Australia due to the absence of a native dog.
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Science
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Ancient Marsupial Found With Specialised Teeth for Eating Snails

Evidence of the existence of specialised ancient marsupials have been found in Australia. They had teeth that were "hammer-like" for crushing snail shells. Lizards living today in rain forests have similar teeth. They had premolars like the teeth in humans located between the molars and canines. Researchers could not determine at first what the strange teeth were used for. It was the first time that such teeth had been found in marsupials.

Like the Tasmanian tiger a marsupial which filled the role of native dog in Australia, so this marsupial more than 10 million years ago, lived in the niche that the pink-tongued skink holds today. This wet rain forest lizard is quite large, about 40 cm in length, so it's ancestor would have been a tough competitor.

The extinct marsupial became extinct when the weather changed in Australia and inland rain forests receded toward the coast. Lizards could survive in the new environment. The marsupial could not.

Riversleigh in northern Australia, a rich source of marsupial fossils, was where the find was made. Indication are that the marsupial was not plentiful even in prehistoric times because so few fossils of the animal have been found.
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Science
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