news-tldr.com

The important facts, the open questions, and the sources — without the churn.

← Latest briefing

Science

324-million-year-old fossil reveals amphibious phase in early insect evolution

A reevaluated fossil from Texas shows early insects retained paddle-like abdominal limbs, filling a gap in the land transition timeline.

Updated Aug 27, 2026 · 13:20 UTC1 reports

The short version

  • Researchers identified a 324-million-year-old stem insect species, Chosha praecursor, that lived an amphibious, semi-aquatic lifestyle.
  • The fossil, originally misclassified as a crustacean, features six walking legs along with paddle-like abdominal appendages.
  • The findings help bridge an 80-million-year gap in the early insect fossil record between aquatic ancestors and fully terrestrial hexapods.

Key facts

  • Researchers led by Chenyang Cai of NIGPAS and Erik Tihelka of the University of Cambridge published findings on the newly identified stem insect Chosha praecursor in Nature on August 26, 2026.[ScienceDaily]
  • The 324-million-year-old fossils were discovered in calcareous claystone concretions within the Tesnus Formation in western Texas.[ScienceDaily]
  • The examined C. praecursor specimens are adult females with body lengths of 32.09 millimeters, reaching 49.66 millimeters when including their median caudal filament and cerci.[ScienceDaily]
  • C. praecursor possessed six walking legs, an ovipositor, and segmented appendages on abdominal segments 1 through 9, with rear abdominal limbs modified into paddle-like structures.[ScienceDaily]
  • The study reevaluated C. praecursor alongside Leverhulmia from Scotland and an unnamed hexapod from Illinois, concluding all three belong to a primitive stem insect lineage.[ScienceDaily]

Sources