Alzheimer’s Disease (AD) is a familial or sporadic severe neurodegenerative disorder that leads to short-term memory impairment followed by progressive cognitive deterioration of executive functions. AD frequency is increasing with a consequent socio-economic burden and there is an urgent need to understand its aetiological complexity, find reliable animal models and identify effective therapeutic treatments. AD diagnosis relies on a series of neuropsychiatric criteria and the detection of two pathognomonic protein aggregates in the brain parenchyma: amyloid plaques and neurofibrillary tangles. The concurrence of these aggregates seems to be mostly present in humans. In this issue, Vacher and colleagues demonstrate the notable coexistence of AP deposition and hyperphosphorylated tau in the brains of dolphins. Here we discuss the relevance of this finding and how they could help understanding AD