Abstract : Paleoart is an important artistic manifestation and widely used in paleontological study, education, museum exhibitions, and media. Paleoart is considered here as the artistic works that pretend to show or rebuild prehistoric life according to the recent knowledge and scienti ic evidence. Here, we summarize the meaning and the importance of paleoart in the paleontological world with the case studies from crocodile and dinosaur fossils from Thailand. In this report, five extinct crocodilomorphs and six theropod (meat-eating) dinosaurs were reconstructed based on scienti ic reports. If their skulls and some important elements were found, then the reconstruction would be based on those materials. If their skulls were not found then the reconstruction would be inferred from the more complete materials of their closed relatives. So, the more complete materials we have the more accuracy the reconstruction is. Five Groups of crocodilomorphs (Pholidosauridae, Goniopholididae, Atoposauridae, Neosuchia, and Alligatorinae) have been reconstructed. Four of them were found from northeastern Thailand and one from southern Thailand. The ancient croc named Chalawan was first reported in 1980. It consists of a lower jaw only. Without skull materials, the reconstruction of Chalawan was first based on the old hypothesis that it was co-generic with Sunosuchus from China. Thus it was reconstructed based on the skulls and skeletons of Sunosuchus. With newly found specimens including skull elements and new hypothesis published later in 2013, the shape of the snout of Chalawan has been slightly modiied from the old reconstruction. by SAMATHI A. Steinmann-Institut für Geologie, Mineralogie und Paläontologie, Universität Bonn, Nussallee8 53115 Bonn, Germany ART IN PALEONTOLOGY: THE RECONSTRUCTION OF EXTINCT ANIMALS 21