Reconstructing the behavior of extinct species is challenging, particularly for those with no living analogues. However, damage preserved as paleopathologies on bone can record how an animal moved in life, potentially reflecting behavioral patterns. Here, we assess hypothesized etiologies of pathology in a pelvis and associated right femur of a Smilodon fatalis saber-toothed cat, one of the best-studied species from the Pleistocene-age Rancho La Brea asphalt seeps, California, USA, using visualization by computed tomography (CT). The pelvis exhibits massive destruction of the right hip socket that was interpreted, for nearly a century, to have developed from trauma and infection. CT imaging reveals instead that the pathological distortions characterize chronic remodeling that began at birth and led to degeneration of the joint over the animal's life. These results suggest that this individual suffered from hip dysplasia, a congenital condition common in domestic dogs and cats. This individual reached adulthood but could not have hunted properly nor defended territory on its own, likely relying on a social group for feeding and protection. While extant social felids are rare, these fossils and others with similar pathologies are consistent with a spectrum of social strategies in Smilodon supported by a predominance of previous studies.

中文翻译：

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计算机断层扫描显示已灭绝的更新世剑齿虎猫的髋关节发育不良

重建灭绝物种的行为具有挑战性，特别是对于那些没有类似生物的物种。然而，保留为骨骼上的古病理学的损伤可以记录动物在生活中的移动方式，可能反映行为模式。在这里，我们评估了致命剑齿虎骨盆和相关右股骨中病理学的假设病因剑齿虎，是美国加利福尼亚州更新世时代 Rancho La Brea 沥青渗流中研究最深入的物种之一，使用计算机断层扫描 (CT) 进行可视化。近一个世纪以来，骨盆显示出右侧髋关节窝的巨大破坏，这被解释为由外伤和感染发展而来。相反，CT 成像显示，病理性扭曲表征了从出生开始并导致动物一生中关节退化的慢性重塑。这些结果表明，这个人患有髋关节发育不良，这是一种在家犬和猫中常见的先天性疾病。这个人成年了，但无法正常狩猎，也无法独自保卫领土，很可能依靠社会群体来获得食物和保护。虽然现存的社会猫科动物很少见，Smilodon由先前研究的优势支持。