Dinosaur-to-bird transition · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.
En anglais

From feathered dinosaurs to birds: the fossil evidence

Science · Dinosaurs & Paleontology · ages 11-13
Name ______________________   Date ____________
  1. No living bird has true teeth in its jaws.

    Circle one:   True   False

  2. How can researchers estimate Anchiornis feather colors from preserved evidence?

    • Compare the surrounding rock color with known colors of living feathers.
    • Compare feather lengths and outlines with those of living bird feathers.
    • Compare preserved pigment structures with those in living bird feathers.
  3. Which fossil matches the description of short, fuzzy filaments rather than broad flight feathers?

    • Fossils of Sinosauropteryx
    • The fossils of Microraptor
    • Fossils from Archaeopteryx
  4. A Microraptor reconstruction shows long feathers on its arms but none on its legs. Which correction follows from its fossils?

    • Move its long arm feathers to its tail, leaving the arms and legs bare.
    • Keep its long arm feathers and add long feathers onto both of its legs.
    • Shorten its long arm feathers into fuzz, leaving both legs unfeathered.
  5. Sinosauropteryx had short, fuzzy filaments rather than broad flight feathers. Which possible use follows from that structure?

    • Forming broad wing surfaces that could support sustained powered flight
    • Forming flat paddle surfaces that could push its body through the water
    • Trapping air near its body, which could slow the rate of body heat loss
  6. Why can some deposits in northeastern China preserve delicate feather details?

    • Fine sediments and rapid burial could help preserve feather impressions.
    • Coarse sediment records smaller feather details than fine sediment does.
    • Long exposure before burial preserves feathers better than rapid burial.
  7. A display calls Anchiornis the only dinosaur with reported feather color evidence. Which fact requires the label to change?

    • Anchiornis also had long feathers on both its arms and its legs.
    • Color evidence was reported for Sinosauropteryx and Microraptor.
    • Microraptor had long feathers on its arms, legs and on its tail.
  8. A poster shows ground-up and trees-down proposals for flight. Which caption correctly describes their place among scientific ideas?

    • Two proposed routes covering all possible starting movements for flight
    • Two proposed stages, with running then gliding before flapping develops
    • Two proposed routes among others that scientists can test with evidence
  9. A fossil has legs suited to running and feathered arms. Which study would best test whether its wing use could fit a ground-up route?

    • Test whether its body and wing model could glide down from tree branches.
    • Test whether its body and wing model could slow a fall from a high perch.
    • Test whether its body and wing model could gain lift during a short leap.
  10. A display arranges Sinosauropteryx, Microraptor and Archaeopteryx by feather traits. Which label describes what that sorting rule establishes?

    • A comparison of feather traits between three fossil species
    • A timeline of fossil dates inferred from feather complexity
    • An ancestor sequence inferred from feather complexity alone
LightMySky · lightmysky.comW1-mt_mqQ-DtH5m--s1

Answer key

For grown-ups. Fold this page away before handing over the rest.

From feathered dinosaurs to birds: the fossil evidence W1-mt_mqQ-DtH5m--s1

  1. True · Living birds lack true jaw teeth. This claim concerns teeth, not every feature found in Archaeopteryx.
  2. Compare preserved pigment structures with those in living bird feathers. · Preserved pigment structures can be compared with those in living feathers. Rock color and feather outline are not the pigment comparison taught here.
  3. Fossils of Sinosauropteryx · Sinosauropteryx had the short, fuzzy covering described here.
  4. Keep its long arm feathers and add long feathers onto both of its legs. · Microraptor had long feathers on its arms and legs. Add the missing leg feathers while keeping the arm feathers.
  5. Trapping air near its body, which could slow the rate of body heat loss · A fuzzy covering could trap air and reduce heat loss. This supports insulation as a possible use, not a proven purpose.
  6. Fine sediments and rapid burial could help preserve feather impressions. · Fine sediment can record delicate structures, and rapid burial can help preserve them. The alternatives reverse those preservation conditions.
  7. Color evidence was reported for Sinosauropteryx and Microraptor. · Reports of color evidence for Sinosauropteryx and Microraptor challenge the exclusive label. Feather locations alone do not establish reported color evidence.
  8. Two proposed routes among others that scientists can test with evidence · Ground-up and trees-down are two proposals among others. They are not an exhaustive pair or a required sequence of stages.
  9. Test whether its body and wing model could gain lift during a short leap. · A ground-up test examines wing use during running or leaping. Tests beginning above the ground address different starting movements.
  10. A comparison of feather traits between three fossil species · Sorting by feather traits establishes a trait comparison. It does not supply the age or ancestry evidence needed for a timeline or ancestor sequence.
Worksheet · LightMySky