To amend chapter 3 of title 36, United States Code, to designate the American mastodon as the national fossil mammal and the Tyrannosaurus rex as the national fossil dinosaur of the United States, and for other purposes.

Bill overview

• Bill: HR 9191
• Session: 119
• Congress: United States
• Introduced: 2026-06-08
• Current status: Referred to the House Committee on the Judiciary (as of 2026-06-08)
• Primary purpose: Amend chapter 3 of title 36, United States Code, to designate two national symbols:
  • American mastodon as the national fossil mammal
  • Tyrannosaurus rex as the national fossil dinosaur
• Sponsors:
  • Co-sponsors include Dusty Johnson, Tracey Mann, Nick Langworthy, Debbie Dingell, Erin Houchin, Celeste Maloy

Key provisions and changes

• Amend Title 36 (Patriots and National Observances, Ceremonies, and Symbols) – Chapter 3 governing national symbols
• Designations:
  • National fossil mammal: American mastodon (Mammut americanum)
  • National fossil dinosaur: Tyrannosaurus rex
• Implications of designation:
  • Establishes official national fossil symbols at the federal level
  • Signals recognition of the mastodon and T. rex in federal statute as emblematic fossils for the United States
• Administrative/clerical alignment:
  • Likely requires updating cross-references and related bureaucratic materials to reflect these new designations
  • May inform federal observances, educational materials, and commemoration activities

who/what is affected

• Government and offices:
  • Federal agencies responsible for national symbols and observances under Title 36
  • Agencies involved in education, culture, history, and natural heritage messaging
• Public-facing entities:
  • Museums, cultural institutions, educators, and event organizers may reference the national fossil mammal and national fossil dinosaur in programs and exhibits
• General public:
  • Creates a shared, official reference for the mastodon and T. rex as nationally recognized fossils

Procedural and timeline considerations

• Introduction and referral:
  • Introduced in the House and referred to the Committee on the Judiciary
• Next steps:
  • Committee consideration, potential amendments, and votes
  • If approved, bill would proceed to the House floor for debate and passage
  • If passed by the House, would move to the Senate for consideration (not covered in current action history)
• Effective date:
  • No explicit effective date stated in the summary; typically, designations become effective upon enactment into law or as specified within the final statute

Potential impact and context

• Symbolic significance:
  • Provides formal federal recognition of two prominent prehistoric creatures as national fossils
  • May influence educational initiatives, commemorative programs, and public outreach around paleontology
• Educational and cultural impact:
  • Could guide curricula, museum programming, and national storytelling about natural history
• Legal and statutory scope:
  • Adds to the catalog of national symbols in Chapter 3 of Title 36, alongside other designations such as national rivers, trees, and birds

If you’d like, I can compare this bill to existing national symbols or provide a brief historical context on prior fossil designations and how similar designations have been implemented in law.