Fossil scans suggest tiny-armed dinosaurs evolved as specialized insect hunters

Across the long arc of dinosaur evolution, nature appears to have arrived at the same unusual solution more than once: shrinking the arms. A new study of 85 fossilized theropods reveals that diminutive forelimbs evolved independently in at least five separate lineages, with the alvarezsauroids offering the most compelling evidence that small arms were not a flaw but a feature — purpose-built for breaking into insect colonies and extracting concentrated nutrition. What once seemed like an evolutionary embarrassment may instead be a testament to the quiet ingenuity of specialization.