Although taxonomic proficiency is a prerequisite for understanding ideas central to biology, previous research has established that learners frequently misclassify animals by not following the tenets of accepted taxonomic rubrics. This has immediate relevance with the recently revised English National Curriculum now requiring concepts of animal classification to be taught to 5–6 year-olds. The current study represents an attempt to explore how preschool children aged 3–5 years classify animals, and patterns in the ways in which their taxonomic knowledge might progress with age were sought to illuminate potential origins of naive conceptions in the early years. A quantitative approach was employed with a sample of 75 children utilising a structured interview method to determine their ideas about the taxonomic labels animal, fish, amphibian, reptile, bird, mammal and insect. Findings revealed common learning trajectories as children’s prototypes developed from 3 to 5 years. These trajectories confirmed that the preschool children held many of the same naive conceptions as those previously reported in older learners. Some of these conceptions started to dissipate with age; however, others began to emerge in the older children within the sample, representing a decline in performance with age. This decline is concerning though can be accounted for by contemporary categorization theory, giving support to the view that science misconceptions can emerge in the early years due to natural maturation (cognitive factors), as well as exposure to formal and informal learning experiences (socio-cultural factors). To supplement established conceptual change strategies, which deal with already-formed misconceptions, it is proposed that there be a fresh research emphasis towards conceptual creation where acceptable scientific ideas are seeded at the earliest years of schooling. Accordingly, the role of early years educators would become fundamental to effective science education.