Smilodon fatalis siblings reveal life history in a saber-toothed cat

The saber-toothed cat Smilodon fatalis is known predominantly from predator trap'' deposits, which has made many aspects of its life history difficult to infer. Here, we describe an association of at least two subadult and one adult S. fatalis from Pleistocene coastal deposits in Ecuador. The assemblage likely derived from a catastrophic mass mortality event, and thereby provides insights into the behavior of the species. The presence of a P-3 in the subadult dentaries suggests inheritance, a rare instance of familial relatedness in the fossil record. The siblings were at least two years old and were associated with an adult that was likely their mother, indicating prolonged parental care in S. fatalis. Comparison with the growth of pantherine cats suggests that S. fatalis had a unique growth strategy among big cats that combines a growth rate that is similar to a tiger and the extended growth period of a lion.

Automated summary

This study describes a fossil assemblage of saber-toothed cats from Pleistocene coastal deposits in Ecuador, indicating a catastrophic mass mortality event involving at least one adult and two subadults. The fossil record shows familial relatedness between the subadults and the adult, suggesting prolonged parental care in Smilodon fatalis during their juvenile years.