CollectA Caiuajara with Movable Jaw DeluxeCollectA Caiuajara with Movable Jaw Deluxe CollectA Model 88839 Product Dimensions: 19 x 9. 5 x 23. 5 cm Age: 3 years and up The Caiuajara is notable for its huge head crest that changed shape as the animal matured. Both sexes appear to have had crests, although these may have been differently patterned. they were presumably used during mating rituals as species recognition or to show sexual maturity. The CollectA model shows an adult on the ground.