World 7 · How Old Is That Bone? · 12 min · PRO
Dating volcanic ash around the fossil
The sandwich method and the uranium–lead clock
PRO · Dinosaur Dig
World 7: How Old Is That Bone? is part of PRO
The first world of Dinosaur Dig is free. PRO opens the other 24 lessons in 6 worlds — simulations, quizzes and all.
PRO includes
- All 60 labs — every world, every lesson
- Practice exams and certificates
$8.33/mo, billed yearly ($99.99) · or $39.99 monthly