The now-extinct Myotragus balearicus, or "mouse goat," stood a mere 19 inches high, but its small stature is by no means its most unusual trait. Paleontologists have determined that this diminutive goat had more in common with reptiles than mammals.
In a paper published in the new issues of Proceedings of the National Academy of Sciences, researchers from the Autonomous University of Barcelona claim that Myotragus was actually similar to the crocodile in terms of its bone structure and growth. Unlike warm-blooded mammals, which generally have quick growth rates, fast movements, and fairly large brains, the mouse goat's bone structure indicates that it had a very low metabolism, slow growth rates, and smaller brains. Like crocodiles and other reptiles, the bones of the Myotragus have parallel growth lines, indicating that the creature's growth would start and stop cyclically. The bones of other mammals generally show uninterrupted growth.
The study authors believe this indicates that the Myotragus was slow-moving, like cold-blooded animals, and that it needed fewer resources to survive. This solves one of the key mysteries surrounding the goat: how it managed to thrive for 5.2 million years on Majorca, an island with extremely little food. It also helps explain why the goats died off so quickly when humans arrived on Majorca 3000 years ago. Because of its smaller, reptile-like brain, the Myotragus didn't have possess the senses many mammals posses to elude prey, making it an easy target for humans hungering for miniature goat meat.
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