These creatures (all published in official WOTC D&D books) that are definitely part of the ecology of the Sauric Isles are posted here. If you see any others that you feel need to be included, please share your comments/suggestions.
Sandstorm
Protoceratops
Werecrocodile
Giant Banded Lizard
Stormwrack
Plesiosaur
Archelon
Icthyosaur
Mosasaur
Monster Manual II
Cryptoclidus
Allosaurus
Ankylosaurus
Quetzalcoatlus
Spinosaurus
Seismosaurus
Dire Snake
Dire Toad
Epic Level Handbook
Prismasaurus
Dragon Magazine #318
Compsognathus
Dimetrodon
Diplodocus
Parasaurolophus
Gianotosaurus
Helicoprion
Liopleurodon
Pachycephalosaurus
Pteranodon
Rhamphorhynchus
Stegosaurus
Troödon
Eberron Campaign Setting
Velociraptor
Leaellynasaura
Tapejara (originally called Pteranodon, but different statistics are being used)
Monster Manual III
Battletitan
Swindlespitter
Bloodstriker
Fleshraker
Zezir
Monster Manual/SRD
Deinonychus
Elamosaurus
Megaraptor
Triceratops
Tyrannosaurus
Destrachan
Digester
Shark
---Medium
---Large
---Huge
---Dire
Snake
---Constrictor
------Giant Constrictor Snake
---Viper
------Tiny
------Small
------Medium
------Large
------Huge
Monstrous Centipede
---Medium
Monstrous Scorpion
---Tiny
---Medium
Monstrous Spider
---Tiny
Lizard
---Monitor
Manta Ray
Crocodile
---Giant
Squid
---Giant
Toad
Fiend Folio
Ti-khana Deinonychus
Miniatures Handbook
Cave Tyrannosaurus
Cave Ankylosaurus
Cave Triceratops
Serpent Kingdoms
Ceratosaurus
Draconomicon
Plains Landwyrm
Jungle Landwyrm