Update 2.1 brings many changes to the game, both with the resource pack and with the datapack. The changes for both can be found here:

Added 9 mobs:

• Shantungosaurus - Donkey
• Lambeosaurus - Mule
• Stegosaurus - Sniffer
• Dracorex - Goat
• Gigantoraptor - Strider
• Spider model
• Bristletail - Silverfish
• Whiptail - Cave Spider
• Euoplocephalus - Armadillo

 Changes to the following dinosaurs:

• Small fix to Parasaurolophus model
• Adjusted Therizinosaurus size
• Remodeled Utahraptor entirely, and added Raptor Armor

Changed/added 40 new items:

• Textures for all meats
• Custom leather hides for each* dinosaur
• Item drops for all new mobs
• Custom foods
• Music Disc "Extinct" by RedWolf
• Sauropod banner pattern
• Project Extinction Painting
• Several lore items from the YT series
• The Morning Star (Mace upgrade)

9 Advancements:

• Prehistoric Cowboy
• Mobile Fortress
• Top of the Morning
• Does it Taste like it Smells?
• Good Soup
• Uncover the Past
• A Key to the Past
• Fossil Finder
• Fossilized Tracks

Added 2 structures:

• Ancient Digsite
• Time Machine