Abstract:

Background & Aims: The crocodile lizard (Shinisaurus crocodilurus), has experienced a dramatic decline in wild populations due to historical habitat loss, human-induced poaching driven by international pet trade, and other anthropogenic pressures; it currently faces an extremely high risk of extinction across its entire distribution range in China and Vietnam. It is assessed as Endangered by the IUCN Red List and listed as a National Class I Protected Wildlife species in China, and it is also listed as a protected species in Vietnam. Beyond its irreplaceable conservation value, S. crocodilurus represents an ideal model for investigating evolutionary history and ecological adaptation in lizards, owing to its unique systematic position, ancient evolutionary lineage, distinctive life-history traits, and high sensitivity to environmental change. This review aims to synthesize current research progress on S. crocodilurus and to identify key scientific issues relevant to its conservation and management. 

Progress: Since its discovery, substantial advances have been made in studies of S. crocodilurus, encompassing its taxonomic status and fossil record, historical range shifts and population status, habitat selection, genetic diversity and phylogeographic structure, as well as behavioral rhythms and thermal physiology in holding facilities. Recent molecular phylogenetic and genomic studies have clarified the pivotal position of S. crocodilurus within anguimorph lizards and revealed pronounced genetic differentiation among geographically distinct populations in China and the Vietnamese subspecies. Genetic and genomic evidence indicates that extant populations exhibit overall low genetic diversity, although long-term population bottlenecks may have been accompanied by a certain degree of genetic purging. Field surveys and ecological studies show that habitat loss and fragmentation, together with human disturbance, have imposed persistent pressures on wild populations. Moreover, climate-scenario-based models suggest that future climate change may substantially exacerbate declines in habitat suitability and increase long-term persistence risks. 

Prospects: Based on a systematic synthesis of existing research, this review highlights key scientific challenges in the conservation of S. crocodilurus and outlines priority directions for future research and management. These include improving long-term population monitoring, assessing adaptive potential under ongoing climate change, standardizing genetic management of captive-breeding populations, developing non-invasive indicators such as body coloration for individual assessment, and optimizing reintroduction programs and post-release monitoring strategies. Together, these efforts aim to provide a scientific foundation for evidence-based conservation and management decisions for the crocodile lizard.

Key words: Shinisaurus crocodilurus, artificial breeding, reintroduction, conservation genetics