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paleontology

The pains of a sloth

A giant sloth that lived tens of thousands of years ago in what are now the scrublands of Pernambuco State was probably walking around for years with excruciating neck pain. Paleontologist Fernando Henrique de Souza Barbosa identified extensive bone damage in the fossilized second vertebra of the animal, a land-dwelling quadruped nearly six meters long and weighing almost five tons (in other words, bigger than an elephant). Geologist José Lins Rolim, now a retired professor from the Federal University of Pernambuco (UFPE), found the fossilized vertebra of Eremotherium laurillardi in the early 1970s in a geological formation commonly found in Northeast Brazil called a fossiliferous “tank” – a type of depression in granitic rocks, in which layers of sediment are deposited from time to time. The specimen, stored at the UFPE paleontology museum, was recently studied by Barbosa and two colleagues (International Journal of Paleopathology, September 2014). “It was probably living with severe pain,” says Barbosa, a PhD student at the Federal University of Rio de Janeiro (UFRJ). The type of damage he identified in the fossil was an osteophyte, popularly known as a bone spur, which is a bony outgrowth at the border of a joint. It was a rare find. “Finding fossils is hard enough already, and it’s even harder to find one with a problem that begins in a joint and takes time to affect the bone,” he says.

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