1. Eating plan that attempts to mimic Stone Age conditions → PALEODIET
10. It's different from randomness, mathematically → CHAOS
15. Unsolved mysteries → OPENCASES
16. Pasta shape similar to ziti → PENNE
17. Despite its name, it's not alcoholic → GINGERALE
18. Subscription prices → RATES
19. Celery unit → STALK
20. Pineapple and Cranberry, for two, in N.Y.C. → STS
22. Material for a certain pocket → PITA
23. Shape of a charm that Simone Biles wears on a necklace → GOAT
25. "Toy Story" antagonist → SID
27. Where to set a cocktail garnish → RIM
28. Command that initiates a chase → GOFETCH
31. "Avengers: ___" (film in Marvel's Infinity Saga) → ENDGAME
33. Resource used in 67-Across → ORE
34. ___ paneer (classic vegetarian Indian dish) → SAAG
36. Be in one's good ___ → GRACES
37. Ooze → SEEP
39. Live → DWELL
41. Board game that begins with players choosing college versus career → LIFE
42. "I canNOT handle this right now" → SODONE
44. One option in a subscription service → TIER
46. "I told you!!" → SEE
47. They form when snow melts and refreezes → ICEDAMS
49. Created unpleasant driving conditions, in a way → SLEETED
51. "___ supuesto!" ("Of course!," in Spanish) → POR
52. Insta post → PIC
53. Needing a 34-inch inseam, maybe → TALL
54. Roman Empire invader → GOTH
56. Verb in each of the first three sentences of the Gettysburg Address → ARE
58. British natural historian Attenborough → DAVID
61. They're the subject of more than 200 million catalogs a year → IKEAS
63. Common things in processed foods → ADDITIVES
66. Iranian money → RIALS
67. Video game in which users build tools from raw resources → MINECRAFT
68. Fruit that can be used to add highlights to your hair → LEMON
69. Liner notes? → SEASHANTY