Overview
- A peer‑reviewed paper published Sept. 10, 2026 reports micro‑CT scans of a golf‑ball‑sized coprolite from Montana’s Hell Creek Formation that contain multiple feathers, tiny gar fish scales, and small bird leg bones.
- Researchers identify the bird remains as hesperornithiform, an extinct loon‑like diving bird, and describe two feathers with modern features including a square shaft with a sponge‑like center not previously seen in Mesozoic specimens.
- The coprolite was produced by a large predatory theropod based on size and contents, with authors noting Tyrannosaurus rex or Nanotyrannus as plausible but unconfirmed candidates.
- Lead authors advance a developing hypothesis that hesperornithiforms combined waterproof limb feathers with primitive fuzzy body feathers, and that poorer body insulation may have contributed to their extinction while crown birds survived; the idea requires more specimens to test.
- The study demonstrates that non‑destructive CT and micro‑CT of coprolites can reveal rare soft tissues and whole predator–prey chains, prompting calls for systematic scanning of museum collections to expand knowledge of feather evolution and ancient food webs.