geologic time
Across
- 1. istheoldesteraofthephanerozoniceon
- 4. arethelongestunitsofgeologictime
- 6. isabodyofwaterformedwhenoceanwaterfloodscontients
- 8. weremesozoicmarinereptileswithsmallheadlangnecksandflippers
- 11. erasaresubdivided
- 12. istheseparationofapopulationoforganismsfromtherestofitsspeciesdueto
- 14. weredomiantmesozoiclandvertebratesthatwalkedwithlegspositioneddiretlybelowthehips
- 15. theextintionofmanyspeciesonearthwithinashortperiodoftime
Down
- 2. subdividedintosmallerunitsoftime
- 3. periodsaresubdivided
- 5. istheyoungesteraofthephanerozoiceon
- 7. connectstwocontinentspreviouslyseparated
- 9. isanacientlandmasswhichseparatedintopresent-daycontients
- 10. isthemiddleeraofthephanerozoiceon
- 13. isanoxygen-poorenviromentwhereovertimeplantmaterialchagesintocoal