Conservation and management of important species and landscapes are hampered by a lack of knowledge of historical conditions. Preserved animals, or their parts, can contain primary evidence of environmental conditions and the biology of the animal itself. Through the analysis of their biological structures, aspects of their life – e.g. growth, age or movement – can be yielded. The aim of this study was to explore the utility of informal collections of taxidermy Murray cod (Maccullochella peelii) as records. The accessibility, and a life history metric, total length, of Murray cod mounts was assessed. Total length of fish is an indication of the carrying capacity of rivers they were harvested from. The taxidermy mounts were accessed through a broad citizen survey, and their form, interpretive records, shape and curation investigated. Hundreds of collections, comprising a total of 458 mounts were discovered, 362 of which were heads. Weight was the most commonly recorded life history trait. Mounts were harvested from 1952-2014, across an area consistent with the extant populations (~1,000,000 km2). The measurements on 60 whole and 172 head mounts and 51 living individuals identified robust lifelike features, from which growth relationships were developed. Comparisons between the taxidermy with live specimens demonstrates that total length of fish can be predicted from their preserved head shape, irrespective of the form. As head mounts are the most common form, the ability to predict length from these apex predator specimens provides insight into past environmental conditions. Collectively, the comprehensiveness of the informal collections, associated interpretative records and verification of the persistence of lifelike features, is a demonstration of the potential of these specimens as primary biogeographic records. Given the receptiveness of the stewards to scientific enquiry, using existing long-lived apex predator fauna collections of taxidermy could open up a new area of historical ecology research.