A 324-million-year-old fossil reveals an insect that lived between land and water

Representative Image of Chosha praecursor, an early insect with paddle-like abdominal appendages in a prehistoric landscape (AI-generated image) Today, insects occupy nearly every terrestrial environment on Earth and account for more described species than any other animal group, yet the earliest stages of their evolutionary history remain poorly documented. A newly described species from western Texas, named Chosha praecursor, now offers a rare glimpse into that missing chapter. The animal lived roughly 324 million years ago during the Late Mississippian and combined recognisably insect-like anatomy with a body plan unlike that of any living insect. It had three pairs of thoracic walking legs, but its abdomen retained segmented appendages across all nine abdominal segments, with the posterior ones modified into broad, paddle-like structures. The anatomy, combined with evidence that the animal lived in a near-shore, shallow-water environment, suggests a semi-aquatic lifestyle. Rather than showing an insect that had already completed the transition to life on land, the fossil provides evidence that some early insects retained and modified ancestral aquatic structures while adapting ...