Across
- 4. animals with backbones, including fish, amphibians, reptiles, birds, and mammals
- 6. multicellular organisms that produce their own food through photosynthesis and form the base of most ecosystems
- 15. large animals, often referring to those from prehistoric times like mammoths or giant sloths
- 17. soft-bodied animals with stinging cells; includes jellyfish, corals, and sea anemones
- 18. the first large, multicellular organisms, appearing before the Cambrian explosion
- 20. a fossil species showing both dinosaur and bird traits; an early example of flight in vertebrates
- 22. a condition in which systems [like ecosystems or climate] resist drastic change or bounce back after disruption
- 23. the current eon, spanning about 541 million years, marked by abundant fossil evidence and complex life
- 26. a geological time period marked by extreme ice ages, from about 720 to 635 million years ago
- 27. invertebrates with exoskeletons, segmented bodies, and jointed limbs; includes insects, spiders, and crustaceans
- 28. multicellular, heterotrophic organisms that typically move and respond to their environment
- 29. a hair-like covering found on mammals that provides insulation and sensory feedback
- 30. a time around 485 to 443 million years ago when marine life diversified rapidly
- 31. specialized organs in mammals that produce milk to nourish offspring
- 33. multicellular animals that evolved from simpler organisms and include most living animal species
- 34. a group of reptiles that dominated earth for over 150 million years until their extinction at the end of the creataceous
- 36. extinct marine arthropod with segmented bodies and exoskeletons, common in early Paleozoic oceans
- 37. a kingdom of organisms that break down organic matter; includes mushrooms, molds, and yeasts
- 38. a relatively short period in geological history when large numbers of species die out worldwide
- 40. an ancient supercontinent believed to have formed before columbia and broken apart before pangea
- 41. a hypothesis that earth was once entirely or nearly covered in ice during periods like the cryogenian
Down
- 1. ice-like compounds that trap gases such as methane
- 2. the ability to walk upright on two legs; a defining trait of human ancestors
- 3. the state of being made of many cells that work together, allowing for greater complexity
- 5. the rapid evolution of diverse species from a common ancestor
- 7. tiny openings in plant leaves that control gas exchange and help regulate water loss
- 8. a series of organisms that depend on one another for food, transferring energy from producers to consumers
- 9. a phylum of animals that includes vertebrates and others with a notochord, dorsal nerve cord, and tail
- 10. a geological period that ended with the Permian mass extinction, about 252 million years ago
- 11. a rapid burst of evolutionary activity about 540 million years ago when most major animal group appeared
- 12. marine animals with cilia used for movement; also called comb jellies
- 13. an impact site in Mexico linked to the asteroid that caused the extinction of the dinosaurs
- 14. the geological period following the Permian, when dinosaurs first appeared
- 16. a fossil-rich deposit in Canada that provides detailed evidence of life during the Cambrian explosion
- 19. an ancient supercontinent that existed around 1.8 to 1.5 billion years ago
- 21. the ability to adapt behavior based on experience; common in animals with advanced brains
- 24. a major extinction event driven by rising global temperatures and altered climates
- 25. the largest extinction event in earth's history, wiping out around 90% of species
- 32. programmed cell death that helps shape developing organisms and maintain healthy tissues
- 35. vertebrates that lay eggs with protective membranes or carry embryos internally, including reptiles, birds, and mammals
- 39. the part of the mammalian brain involved in higher-order functions like reasoning and problem-solving