Between 50% and 70% of snakes and lizards on the Guadeloupe Islands in the Caribbean went extinct after European colonists arrived on the archipelago, according to a study of 43,000 reptile bone remains from 6 islands. In contrast, the findings suggest that Indigenous populations who lived on the islands for thousands of years before the colonists' arrival did not diminish the diversity of local reptiles. The study points to the importance of considering fossil data when investigating how humans have impacted biodiversity. While the extinctions of large, charismatic animals have captured the attention of researchers and the general public alike, organisms such as reptiles have garnered less interest, including fewer systematic archaeology and paleontology studies across multiple sites within a given region. To fill this research gap, Corentin Bochaton and colleagues analyzed the fossilized remains of 16 taxa from 31 sites on the Guadeloupe Islands, which they sorted into four groups: the Late Pleistocene, the Holocene before the arrival of humans, the Indigenous habitation period, and the modern period, beginning 458 years ago. The researchers used this data to reconstruct the evolutionary history and diversity of these reptiles over the past 40,000 years, finding that mass extinction of the islands' reptiles occurred over only the last 500 years. The findings suggest these species were highly resilient to the impacts of Indigenous populations on the environment. Additionally, Bochaton et al. revealed that tree-dwelling species were less impacted by the colonists' arrival than ground dwellers, while medium-sized taxa were more vulnerable than smaller reptiles. The data indicate that mammalian predators introduced by the colonists - including cats, mongooses, rats, and raccoons - may have been to blame for the extinctions.