Extant Xenarthra

Xenarthra

Order: Xenarthra
Family: 4
Species: 29

There are four extant families of Xenarthra comprising anteaters, armadillos and sloths. Although they look very different from each other, the Xenarthrans are differentiated from any other mammal by unique articulations called xenarthrales on the lower back vertebrae. These articulations provide extra space for muscle attachment, allowing very powerful front legs used for burrowing and digging. They are also united in their Order by a small brain and very reduced dentition. Anteaters actually have no teeth at all. Their diet is varied between families. Anteaters and armadillos are mainly insectivorous. Sloths are herbivorous, feeding off leaves, shoots and fruits high in up the branches of their arboreal habitats.

 

Anteaters

Anteaters have an elongated snout that enables them to feed on ants and termites. In the same manner as the aardvark the anteater tears open an ant hill or termite mound with its incredibly strong front claws. It then uses its long sticky tongue to capture the insects. Its tongue can protrude more than 60 cm and is covered with miniscule backward pointing spines. Together with very sticky saliva, the spines prevent the ants and termites from escaping their fate. To protect its huge claws, the anteater will walk on its knuckles in the same way as a gorilla. Anteaters can be either nocturnal or diurnal and spend their time wandering their range, which can be up to 25 km2, looking for food.

 

Example species:

Giant Anteater
Myrmecophaga tridactyla

Length: 46-86 cm
Weight: 4-8.5 kg
Social unit: Individual
Region: North of South America
Status: Unconfirmed


Giant anteater (Myrmecophaga tridactyla)
Phoenix zoo, Arizona, USA

 

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Author: Emma-Louise Nicholls
Last updated: 20th November 2005
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Websites produced by students on the MSc Palaeobiology programme in the Department of Earth Sciences at the University of Bristol for academic year 2005-6