Surprising incidence of bone diseases in extinct predators

2023-07-13 11:23:26

Detail from a 1911 illustration of a saber-toothed cat at the La Brea Tar Pits. – ROBERT BRUCE HORSFALL & NHM OF LOS ANGELES COUNTY

MADRID, 13 Jul. (EUROPA PRES) –

Saber-Toothed Cats and Direwolves of the Ice Age experienced a high incidence of bone disease in their joints.

This is confirmed by a study published in the open access journal ‘PLOS ONE’ by Hugo Schmökel of the Evidensia Academy (Sweden) and colleagues.

Osteochondrosis is a developmental bone disease that affects the joints of vertebrates, including humans and several domesticated species. However, the disease is not fully documented in wild species, and reported cases are quite rare.

In this study, Schmökel and colleagues identify signs of this disease in fossil limb bones of Ice Age saber-toothed cats (Smilodon fatalis) and direwolves (Aenocyon dirus) from 55,000 to 12,000 years ago. .

The researchers examined more than 1,000 saber-toothed cat limb bones and more than 500 direwolf limb bones from the La Brea Trenches in the Late Pleistocene, and found small defects in many bones consistent with a specific manifestation of bone disease called osteochondrosis dissecans (OCD).

These defects were observed mainly in the shoulder and knee joints, with an incidence of up to 7% of the bones examined, significantly higher than that observed in modern species.

This study is limited to isolated bones from a single fossil locality.Therefore, further studies in other fossil sites could reveal patterns in the prevalence of this disease and, from there, shed light on aspects of the lives of these animals.

It remains unclear, for example, whether these joint problems would have hampered the hunting ability of these predators. Furthermore, OCD is common in modern domestic dogs, which are highly inbred, so it is possible that the high incidence of the disease in these fossil animals is a sign of declining populations as these ancient species neared extinction.

“This study adds to the growing literature on the paleopathology of Smilodon and direwolf, made possible by the unparalleled sheer size of the exhibits at the La Brea Tar Pits & Museum –highlights–. This collaboration between paleontologists and veterinarians confirms that these animals, although they were large predators that lived through hard times and are now extinct, shared common ailments with the dogs and cats we have in our homes today.”