Monday 12 August 2013

The diet of the Langebaanweg Hyaenids.

Modern Hyenas are among the most highly specialized durophagous (adapted to eating tough food) Mammals ever to live, with powerfully constructed teeth and jaws and enlarged masticatory mussles that allow them to crush bones rapidly, making them formidable predators and scavengers able consume almost all parts of their prey. The earliest Hyenas diverged from the ancestors of the Cats in the Oligocene. These were small Civit-like animals, with a diet probably comprised mainly of insects. Hyenas have clearly become quite highly modified since this time, but how quickly they reached modern dietary preferences is less clear.

In a paper published in the South African Journal of Science on 29 May 2013, Adam Hartstone-Rose of the Department of Cell Biology & Anatomy at the University of South Carolina School of Medicine and Deano Stynder of the Department of Archaeology at the University of Cape Town, examine the teeth and jaws of a number of Hyena specimens from the Early Pliocene Langebaanweg Quarry in Western Cape Province, South Africa, and compare them statistically to the teeth and jaws of modern Cat, Dog and Hyena species in order to access the dietary habits of these ancient Hyenas.

Top left, the skull of Ikelohyaena abronia from the Langebaanweg Quarry. Top Right, detail of the jaw of Ikelohyaena abronia. Bottom left, skull of the modern Hyena, Hyaena hyaena. Bottom right, detail of the jaw of Hyaena hyaena. Hartstone-Rose & Stynder (2013).

Hartstone-Rose and Stynder conclude that while the Hyaenids from the Langebaanweg Quarry are superficially as robust, if not more so, as modern species, they are not well adapted to a durophagus diet, being apparently more dog like in dietary preference. This suggests that the highly specialized morphology of modern Hyenas is a recent evolutionary innovation.

The location of the Langebaanweg Quarry. Hartstone-Rose & Stynder (2013).

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